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1
Granger, Julie. "Iron acquisition by heterotrophic marine bacteria." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0002/MQ44173.pdf.
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Thorpe, Anthony P. "Regional and global analyses of bacterial abundance relations in Missouri reservoirs /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p1426107.
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Krey, Whitney B. "Siderophore production by heterotrophic bacterial isolates from the Costa Rica upwelling dome /." Online version of original thesis, 2008. http://hdl.handle.net/1912/2394.
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Jagmann, Nina [Verfasser]. "Interspecific interactions of heterotrophic bacteria during chitin degradation / Nina Jagmann." Konstanz : Bibliothek der Universität Konstanz, 2012. http://d-nb.info/1037311930/34.
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Bradshaw, Susan B. "The role of heterotrophic nitrogen fixing bacteria in freshwater biofilms." Thesis, Lancaster University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334358.
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Nicolau, Paula Bacelar V. C. "Novel iron-oxidising acidophilic heterotrophic bacteria from mineral leaching environments." Thesis, Bangor University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321390.
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Junge, Karen. "Bacterial abundance, activity, and diversity at extremely cold temperatures in Arctic sea ice /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/10980.
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Elifantz, Hila. "Structure and function of microbial communities processing dissolved organic matter in marine environments." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 127 p, 2007. http://proquest.umi.com/pqdlink?did=1251898401&Fmt=7&clientId=79356&RQT=309&VName=PQD.
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King, Laura Kathryn. "Response of indigenous heterotrophic groundwater bacteria to low organic substrate availability." Thesis, This resource online, 1988. http://scholar.lib.vt.edu/theses/available/etd-08252008-162830/.
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Rattray, Julie. "Studies on activities and diversities of heterotrophic bacteria in acidified lochs." Thesis, Glasgow Caledonian University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327893.
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Rocha, Rafael dos Santos. "Polyphasic characterization of heterotrophic bacteria from shrimp farm environments to tetracyclines." Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=16669.
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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorAntimicrobial agents of tetracycline class has been extensively used in aquaculture for disease control and growth promotion. Thus, the aim of this study was to evaluate the polyphase profile of the bacterial community in shrimp farming environment front antimicrobial classes of tetracyclines, focusing on Vibrio genus. Water and sediment samples were collected four (4) shrimp farms: two (2) in the state of Cearà and two (2) in the state of Rio Grande do Norte, of points: estuary, supply channel, pond and drainage channel. Cultivable heterotrophic bacteria (CHB), with resistance to tetracycline (CHB+TET) and oxytetracycline (CHB+OTC), total Vibrio, positive sucrose Vibrio and sucrose negative Vibrio were surveyed by Standard Plate Count method (SPC). The strains isolated from CHB, CHB+TET, CHB+OTC and Vibrio underwent phenotypic identification. The phenotypic profile of antimicrobial susceptibility of strains of Vibrio and other BHC was compared between the disk diffusion techniques and macrodilution by determining the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) for tetracycline and oxytetracycline antimicrobials. Resistance genes tet(M), tet(S) otr(A) and otr(B) were investigated in strains characterized as phenotypically resistant. Diversity of heterotrophic bacteria is influenced by wet and rainy seasons and also by the different collection points within the shrimp farms. Overall, the CHB, CHB+TET and CHB+OTC and Vibrio counts differ between the collection seasons, with higher measurements during the rainy season to the points of pond and drainage channel. 146 strains of CHB, 57 of CHB+TET and 45 of CHB+OTC were isolated, of which the most representative genera were Vibrio and Enterobacter. A total of 100 strains of Vibrio were isolated, which V. coralliilyticus was the most representative species. Antimicrobial profile of Vibrio and other CHB differed between disk-diffusion and macrodilution techniques, being the macrodilution the most efficient in the characterization of resistance among isolates. All strains of Vibrio and other CHB, phenotypically resistant, presented the tet(M) gene as a determinant of resistance determinat, but tet(S) otr(A) and otr(B) genes were not observed. Thus, it proves that Vibrio genus is most abundant among herotrotrophic bacteria with resistance to tetracyclines, with the bacterial diversity strongly influenced by seasons.
Antimicrobianos da classe das tetraciclinas tÃm sido extensivamente usados em aquicultura para o controle de doenÃas e como promotores de crescimento. Dessa forma, foi traÃado como objetivo geral avaliar o perfil polifÃsico da comunidade bacteriana de ambiente de criaÃÃo de camarÃo frente aos antimicrobianos das classes das tetraciclinas, com enfoque no gÃnero Vibrio. Amostras de Ãgua e sedimento foram coletadas de quatro (4) fazendas de carcinicultura: duas (2) no estado do Cearà e duas (2) no estado do Rio Grande do Norte, dos pontos: estuÃrio, canal de abastecimento, viveiro e canal de drenagem. Foram pesquisadas bactÃrias heterotrÃficas cultivÃveis (BHC), com resistÃncia à tetraciclina (BHC+TET) e oxitetraciclina (BHC+OTC), Vibrio total, sacarose positivos e negativos pelo mÃtodo de Contagem PadrÃo em Placas (CPP). As cepas isoladas de BHC, BHC+TET, BHC+OTC e Vibrio foram submetidas à identificaÃÃo fenotÃpica. O perfil fenotÃpico de susceptibilidade antimicrobiana das cepas de Vibrio e demais BHC foi comparado entre as tÃcnicas de disco-difusÃo e macrodiluiÃÃo, pela determinaÃÃo da ConcentraÃÃo InibitÃria MÃnima (CIM) e ConcentraÃÃo Bactericida MÃnima (CBM) para os antimicrobianos tetraciclina e oxitetraciclina. Os genes de resistÃncia tet(M), tet(S), otr(A) e otr(B) foram pesquisados nas cepas fenotipicamente caracterizadas como resistentes. A diversidade de bactÃrias heterotrÃficas foi influenciada pelos perÃodos de estio e chuvoso e tambÃm pelos diferentes pontos de coleta dentro das fazendas de carcinicultura. No geral, as contagens de BHC, BHC+TET e BHC+OTC e Vibrio e demais BHC diferiram entre os perÃodos de coleta, com quantificaÃÃes superiores no perÃodo chuvoso para os pontos de coleta viveiro e canal de drenagem. Foram isoladas 146 cepas de BHC, 57 de BHC+TET, 25 de BHC+OTC, das quais os gÃneros mais representativos foram Vibrio e Enterobacter. Foi possÃvel o isolamento de 100 cepas de Vibrio, das quais V. coralliilyticus foi a espÃcie mais representativa. O perfil antimicrobiano diferiu entre as cepas de Vibrio e demais BHC entre as tÃcnicas de disco-difusÃo e macrodiluiÃÃo, sendo a de macrodiluiÃÃo a mais eficiente na caracterizaÃÃo de resistÃncia dentre os isolados. Todas as cepas de Vibrio e demais BHC, fenotipicamente resistentes, apresentaram o gene tet(M) como determinante de resistÃncia, no entanto os genes tet(S), otr(A) e otr(B) nÃo foram verificados. Com isso, comprovou-se que Vibrio à gÃnero mais abundante dentre as bactÃrias heterotrÃficas com resistÃncia Ãs tetraciclinas, estando a diversidade bacteriana fortemente influenciada pelos perÃodos do ano.
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Bradley, Paul B. "Multi-system analysis of nitrogen use by phytoplankton and heterotrophic bacteria." W&M ScholarWorks, 2009. https://scholarworks.wm.edu/etd/1539616580.
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Traditional measurements of phytoplankton N uptake have been confounded by bacterial retention on filters used in 15N uptake studies, and such methodological obstacles have limited our understanding of phytoplankton-bacterial interactions regarding N cycling. In this research, uptake of various inorganic and organic N substrates by phytoplankton and bacteria was measured in several marine ecosystems using two distinct approaches: size fractionation into phytoplankton and bacterial size classes, and flow cytometric (FCM) sorting of autotrophic cells. Comprehensive assessments of N uptake dynamics were conducted in Chesapeake Bay, the Mid-Atlantic Bight, and Raunefjord, Norway, with supplementary data collected from the York River, Virginia and the Gulf of Mexico. In Chesapeake Bay, the composition of the dissolved N pool shifted from being dominated by dissolved inorganic N (DIN) in the upper bay to mostly dissolved organic N (DON) in the lower bay. Accordingly, phytoplankton nitrate uptake was highest near the head, whereas uptake of urea and dissolved free amino acids generally increased southward. Nonetheless, ammonium was the dominant form of N used by phytoplankton and bacteria throughout the bay. In the Mid-Atlantic Bight, the surface layer was devoid of DIN but ambient urea concentrations were relatively high and this organic substrate supported a large majority of total measured N uptake. The dissolved N pool in the bottom water consisted of about two-thirds DIN, with ammonium contributing most to total uptake. Bacteria were especially active in the bottom water and contributed over half of the total DIN uptake, and there was evidence of bacterial urea uptake in the surface water. In Raunefjord, a mesocosm approach was used to examine N uptake by a bloom of colonial Phaeocystis as well as the competition between phytoplankton and bacteria for limited N resources. Despite amending with nitrate, ammonium was the primary N form supporting the bloom. In the unfertilized mesocosm, bacteria were responsible for about half the urea uptake, most of the DFAA uptake, and at least a third of DIN uptake. Overall, total dissolved N concentrations and total N uptake decreased from estuarine to oceanic waters, although uptake rates were highly variable within each ecosystem. The reduced N forms, ammonium and urea, were most important to phytoplankton N nutrition, and contrary to traditional belief, urea at times played an important role in bacterial N uptake. With respect to methodological approaches, traditional filtration resulted in significant overestimation of phytoplankton N uptake due to the inclusion of, and 15N enrichment in, bacterial biomass retained on filters. This research represents the first comprehensive assessment of phytoplankton-specific N uptake across various ecosystems. It highlights not only the need for careful qualification of uptake rates measured using traditional approaches, but also the potential application of FCM sorting to more detailed examination of N uptake by phytoplankton in general, but also by specific taxa in various marine ecosystems.
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Entezami, Azam A. (Azam Alsadat). "Aquatic Heterotrophic Bacteria Active in the Biotransformation of Anthracene and Pentachlorophenol." Thesis, North Texas State University, 1985. https://digital.library.unt.edu/ark:/67531/metadc504319/.
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Dominant genera of bacteria were isolated from three river waters during anthracene and pentachlorophenol biotransformation studies. The genera Pseudomonas, Acinetobacter, Micrococcus, Chromobacterium, Alcaligenes, Azomonos, Bacillus, and Flavobacterium were capable of biotransforming one or both of these compounds. These isolates were subjected to further biotransformation tests, including river water and a basal salt medium with and without additional glucose. The results of these experiments were evaluated statistically. It was concluded that only a limited number of the bacteria identified were able to transform these chemicals in river water. The addition of glucose to the growth medium significantly affected the biotransformation of these chemicals. It was also determined that the size of the initial bacterial population is not a factor in determining whether biotransformation of anthracene or pentachlorophenol can occur.
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Bayindirli, Cansu. "Monthly Changes In The Abundance And Biomass Of Picoplankton (heterotrophic Bacteria &." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12608190/index.pdf.
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Within the content of this thesis, it was aimed to understand the changes in the biomass and abundance of heterotrophic bacteria and marine cyanobacteria Synechococcus in time with respect to multitude of ambient physical, chemical and biological factors. For this, monthly samples from discrete depths in the offshore (0-20-40-60-80-100-125-150-175-200 m) and in the near shore (surface and 10 m) stations over a period of one year in the Cilician Basin (eastern Mediterranean) were collected via rosette sampler. Epifluorescent microscope and the image analysis system were used to estimate abundance and biomass of both groups.
Coastal station was more abundant and had much higher bacterial (heterotrophic bacteria) and cyanobacterial (Synechococcus) biomass than the offshore station as it receives substantial amount of freshwater from the nearby Lamas River throughout the year. The surface annual averages for bacterial and cyanobacterial abundance and biomass were 9600000 cells/ml - 56.5 microgram C/l and 400000 cells/ml - 24.1 microgram C/l, respectively, at the coastal station. The surface annual averages for bacterial and cyanobacterial abundance and biomass were 8100000 cells/ml &ndash49.1 microgram C/l and 210000 cells/ml &ndash
10.6 microgram C/l, respectively, at the offshore station. Bacterial population always found to exceed Synechococcus abundance within the water column. In general, bacterial and cyanobacterial abundance and biomass tend to decrease with depth. On a seasonal basis, bacterial population was found excessively dominant at the surface or near-surface waters during the second half of the year. Synechococcus were also found more abundant during late summer and autumn. Temperature and nitrate concentration seemed to affect efficiently the abundance of both populations in the area. Based on Spearman Rank Correlation analysis, highly significant correlations between bacterial abundance as well as biomass and ambient temperature were observed at both stations. However, a significant correlation was found between Synechococcus and temperature only at the offshore station. Significant negative correlations are found between nitrate and bacterial abundance and biomass at both stations and between Synechococcus abundance and biomass only at the offshore station. At the offshore station, salinity was also found to be positively correlated with the bacterial and cyanobacterial abundance and biomass.
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Michelou, Vanessa K. "Uptake of dissolved organic matter and phosphate by phototrophic and heterotrophic bacteria." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 150 p, 2010. http://proquest.umi.com/pqdweb?did=1993328571&sid=7&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Sanz, Sáez Isabel. "Contribution of marine heterotrophic cultured bacteria to microbial diversity and mercury detoxification." Doctoral thesis, Universitat Autònoma de Barcelona, 2021. http://hdl.handle.net/10803/671617.
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Els oceans conten aproximadament un total de 10^29 cèl·lules microbianes. Els bacteris marins són responsables de la major part de la respiració que es produeix en l’oceà i són essencials en els cicles biogeoquímics de la Terra. Estudiar la diversitat bacteriana dels ecosistemes marins i tenir accés als genomes mitjançant estudis dependents o independents de cultiu és important per desxifrar el potencial metabòlic dels bacteris marins.
El cultius ens aporten informació sobre la fisiologia bacteriana, ecologia i contingut genòmic, però la majoria dels esforços en aïllar bacteris marins provenen de la zona fòtica de l’oceà, deixant les profunditats marines menys explorades. En aquesta tesi, tècniques estàndard de cultiu han permès crear una col·lecció marina de cultius de bacteris heterotròfics (MARINHET), composada per més de 2000 aïllats, recuperats de diverses regions oceanogràfiques, de diverses profunditats (superfície, mesopelàgic i batipelàgic) i cobrint diverses estacions i anys. El Capítol 1 descriu la seva taxonomia, diversitat filogenètica i biogeografia i revela que un 37% de les soques aïllades són 100% idèntiques en el gen ribosomal 16S (16S rRNA) entre la zona fòtica (superfície) i afòtica (mesopelàgic i batipelàgic). A més, hem identificat Alteromonas i Erythrobacter entre els gèneres marins heterotròfics més comuns que recuperem en cultiu usant un medi marí estàndard.
Les tècniques tradicionals de cultiu generalment només recuperen una fracció petita de les comunitats bacterianes naturals, fenomen conegut com ‘la gran anomalia de recompte en placa’ i moltes de les soques que s’aïllen pertanyen a la biosfera rara. Tanmateix, no coneixem si aquests patrons, normalment descrits per als bacteris de la zona fòtica, també s’apliquen als bacteris de les profunditats. En el Capítol 2 he combinat els resultats obtinguts mitjançant tècniques dependents i independents de cultiu comparant les seqüències del 16S rRNA de la col·lecció MARINHET contra fragments de seqüenciació massiva del 16S rRNA, tant d’amplicons com de metagenomes, obtinguts de mostres globalment distribuïdes i de diferents profunditats. Trobem que una major proporció dels bacteris de l’oceà profund són cultivables i una fracció important dels aïllats té preferència a un estil de vida adherit a partícules. A més, confirmem que el dogma ‘menys de l’1% dels bacteris són cultivables’ ha de ser revisat ja que trobem variabilitat en les mostres de l’oceà profund, on fins a un 3% de les cèl·lules han sigut cultivades.
Els aïllats bacterians són un excel·lent material per a aplicacions biotecnològiques com la bioremediació de zones marines contaminades. El mercuri és un metall pesat tòxic i la seva forma més perillosa, el metilmercuri (MeHg), es bioacumula a la cadena tròfica marina. No obstant això, es coneix molt poc la tolerància de bacteris marins enfront del mercuri o la fisiologia d’aquelles soques que codifiquen l’operó dels gens de resistència (operó mer). El Capítol 3 descriu els resultats del mapeig funcional dels gens merA i merB, clau en la detoxificació, en una fracció de la col·lecció MARINHET. Ens centrem en dos generes marins, amb un potencial genètic per a la degradació del mercuri conegut, com són Alteromonas i Marinobacter. Revelem que els gens merAB estan àmpliament distribuïts en diferents regions oceanogràfiques i en diverses profunditats. Addicionalment, hem seleccionat una soca d’ Alteromonas mediterranea per a futurs estudis de bioremediació degut a la seva alta tolerància i capacitat de degradació de diferents formes de mercuri.Los océanos contienen aproximadamente un total de 10^29 células microbianas. Las bacterias marinas son responsables de la mayor parte de la respiración que se produce en el océano y son esenciales en los ciclos biogeoquímicos de la Tierra. Estudiar la diversidad bacteriana de los ecosistemas marinos y tener acceso a los genomas mediante estudios dependientes e independientes de cultivo es importante para descifrar el potencial metabólico de las bacterias marinas. Los cultivos nos aportan información sobre la fisiología bacteriana, ecología y contenido genómico, pero la mayoría de los esfuerzos en aislar bacteria marinas provienen de la zona fótica del océano, dejando las profundidades marinas menos exploradas. En esta tesis, técnicas estándar de cultivo han permitido crear una colección marina de bacterias heterótrofas (MARINHET), compuesta por más de 2000 aislados, recuperados de varias regiones oceanográficas, de varias profundidades (superficie, mesopelágico y batipelágico), y cubriendo varias estaciones y años. El Capítulo 1 describe su taxonomía, diversidad filogenética y biogeografía y revela que un 37% de las cepas son 100% idénticas en la secuencia parcial del gen ribosomal 16S (16S rRNA) entre la zona fótica (superficie) y afótica (mesopelágico y batipelágico). Además, hemos identificado Alteromonas y Erythrobacter entre los géneros marinos heterótrofos más comunes que recuperamos en cultivo usando un medio marino estándar. Las técnicas tradicionales de cultivo generalmente solo recuperan una fracción pequeña de las comunidades bacterianas naturales, fenómeno conocido como ‘la gran anomalía de recuento en placa’ y muchas de las cepas que se aíslan pertenecen a la biosfera rara. Sin embargo, no conocemos si estos patrones, normalmente descritos para las bacterias de superficie, también se aplican en las profundidades. En el Capítulo 2 he combinado resultados obtenidos mediante técnicas dependientes e independientes de cultivo comparando las secuencias del 16S rRNA de la colección MARINHET contra los fragmentos de secuenciación masiva del 16S rRNA (de amplicones y metagenomas), obtenidos de muestras globalmente distribuidas y de diferentes profundidades. Una mayor proporción de las bacterias del océano profundo son cultivables y una fracción importante de los aislados tiene preferencia a un estilo de vida adherido a partículas. Además, confirmamos que el dogma ‘menos del 1% de las bacterias son cultivables’ deber ser revisado ya que encontramos variabilidad en las muestras de profundidad, donde hasta un 3% de las células se han podido aislar. Los aislados bacterianos son un excelente material para aplicaciones biotecnológicas, como la biorremediación de zonas marinas contaminadas. El mercurio es un metal pesado tóxico y su forma más peligrosa, el metilmercurio (MeHg), se bioacumula en la cadena trófica marina. No obstante, se conoce muy poco la tolerancia de bacterias marinas frente al mercurio o la fisiológia de aquellas cepas que codifican los genes de resistencia (operón mer). El Capítulo 3 describe los resultados del mapeo funcional de los genes merA y merB, clave en la detoxificación, en una fracción de la colección MARINHET. Nos centramos en dos géneros marinos, con un potencial genético para la degradación del mercurio previamente descrito en la literatura, como son Alteromonas y Marinobacter. Desvelamos que los genes merAB están ampliamente distribuidos en diferentes regiones oceanográficas y en varias profundidades. Adicionalmente, hemos seleccionado una cepa de Alteromonas mediterranea para futuros estudios de biorremediación debido a su alta tolerancia y capacidad de degradación de diferentes formas de mercurio.
The world’s oceans sustain the life for an estimated total of 10^29 microbial cells. Marine bacteria are responsible for most part of the ocean respiration and are key in most biogeochemical cycles of the Earth. Accordingly, the study of the bacterial diversity present in different marine ecosystems is essential, and having access to their genomes through isolation or genomic centric studies is important to decipher their metabolic potential. Isolation of marine microorganisms is fundamental to gather information about their physiology, ecology and genomic content. To date, most of the bacterial isolation efforts have focused on the photic ocean leaving the deep ocean less explored. In this thesis, standard plating techniques allowed to create a marine culture collection of heterotrophic bacteria (MARINHET). More than 2000 isolates were retrieved from samples collected from a variety of oceanographic regions, from different depths including surface, mesopelagic and bathypelagic waters, and also covering different seasons and years. Chapter 1 describes the taxonomy, the phylogenetic diversity and the biogeography of culturable heterotrophic marine bacteria, and reveals that an important percentage of the strains (37%) are 100% identical in their partial 16S rRNA gene between photic and aphotic layers. In addition, we identified Alteromonas and Erythrobacter genera as the most frequently retrieved heterotrophic bacteria from the ocean in standard marine agar medium. It is a long-standing observation that traditional culture techniques only retrieve a small fraction of the microbial diversity found in natural environments including marine ecosystems, what is known as ‘the great plate count anomaly’. In addition, most of the retrieved isolates belong to the so-called rare biosphere. However, we do not know if these patterns, usually described for bacteria living in the photic ocean, also apply for the deep ocean bacteria. In Chapter 2 of this thesis, I combined results from culture-dependent and -independent techniques by comparing the 16S rRNA partial sequences of the MARINHET isolates with 16S rRNA amplicon Illumina TAGs (16S iTAGs) and metagenomic TAGs (miTAGs) from surface, mesopelagic and bathypelagic samples globally distributed. A high proportion of bacteria inhabiting the deep ocean could be retrieved by pure culture techniques and a significant fraction of the isolates preferred a lifestyle attached to particles. Additionally, I revised the axiom that ‘less than 1% of bacteria can be cultured’, finding variability between mesopelagic and bathypelagic samples, where up to 3% of the cells could be cultured. Bacterial isolates also represent a valuable genetic reservoir for biotechnology applications, such as bioremediation strategies of marine polluted environments. Mercury is one of the most toxic heavy metals in the planet and its most dangerous form, methylmercury (MeHg), is being bioaccumulated in the marine food web. However, little is known about the tolerance capacity and phenotypic characterization of marine bacteria codifying the mercury resistance operon (mer operon). Chapter 3 describes the functional screening of merA and merB genes, which are key in the mercury detoxification process, in well know marine genera with described genetic potential for mercury detoxification, such as Alteromonas and Marinobacter. I reported that the merAB genes from these two genera are widely distributed in different oceanographic regions and depths. In addition, I selected a promising candidate, phylogenetically affiliated to Alteromonas mediterranea, for future bioremediation studies due to its high tolerance and degradation ability of different mercury forms.
Universitat Autònoma de Barcelona. Programa de Doctorat en Microbiologia
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Cammack, W. K. Levi. "Dissolved organic matter fluorescence : relationships with heterotrophic metabolism." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=29417.
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Characterizing dissolved organic matter (DOM) composition remains a major unresolved problem in aquatic ecology. "Tryptophan-like" dissolved organic matter fluorescence (FDOM) was found to be a much better predictor of heterotrophic bacterial metabolism in 28 Quebec lakes than dissolved organic carbon (DOC), describing 52, 44, 51 and 55% of the variability in bacterial production (BP), bacterioplankton respiration (BR), total bacterial carbon consumption (TBCC), and total plankton community respiration (CR), respectively. In addition, the study provides indirect support for the view that FDOM represents a product of bacterial activity, rather than a bioavailable substrate. This is the first field study to show that fluorescence spectroscopy can be used to characterize an aspect of DOM composition that is related to bacterial metabolism, and provides results that encourage further exploration of the potential uses of DOM fluorescence spectroscopy as a predictive tool.
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Del, Giorgio Paul A. "Heterotrophy in lake plankton." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41362.
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The overall aim of this thesis was to determine the relative importance of heterotrophy and autotrophy in lake plankton. Empirical analyses using extensive surveys of literature data revealed three specific patterns in metabolism and biomass structure in freshwater plankton. First, the ratio of phytoplankton production to plankton respiration (P/R ratio) tends to be low in unproductive lakes ($<$1), and increases along gradients of enrichment. Second, the contribution of planktonic heterotrophs (bacteria and zooplankton) to community respiration is highest in oligotrophic lakes. Third, planktonic heterotrophs dominate community biomass in oligotrophic lakes, whereas phytoplankton increasingly dominate plankton biomass along gradients of enrichment. These three distinct patterns were then tested simultaneously in a set of lakes that span a wide trophic gradient. Results indicated that the plankton of oligotrophic and mesotrophic lakes were characterized by P/R ratios well below unity, and a high contribution of heterotrophs to both community respiration and biomass. These trends are completely the opposite in the most productive lakes. The plankton communities of oligotrophic temperate lakes are predominantly heterotrophic and extensively utilize external inputs of carbon, and therefore only the plankton of eutrophic lakes conformed to the classical phytoplankton-based food web. In most lakes, excess heterotrophic activity could be supported by inputs of organic matter from the drainage basin. Excess plankton respiration, fueled by allochthonous organic carbon, could represent an important source of CO$ sb2$ to lakes.
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Langenheder, Silke. "Links Between Structure and Function of Heterotrophic Aquatic Bacterial Communities." Doctoral thesis, Uppsala : Department of Ecology and Evolution : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4809.
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Adly, Carol. "The role of iron in the ecology and physiology of marine bacteria /." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97884.
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Despite being abundant in the earth's crust, the concentration of Fe in many oceanic regions is so low that it is limiting to the growth of photosynthetic plankton. Heterotrophic bacteria play key roles in the oceanic cycling of carbon and nutrients, but it is unclear whether they can be Fe-deficient in nature, or what possible effects Fe-deficiency might have on their ecology and physiology. In chapter 1, I investigated the response of a natural bacterial community to a mesoscale Fe-enrichment experiment in the northeast subarctic Pacific. The addition of Fe to surface waters caused a rapid stimulation of bacterial growth and production, and induced the organic Fe uptake systems of bacteria. These findings suggest that bacteria responded directly to increased Fe availability, and may be Fe-deficient in situ. In chapter 2, I examined the effects of Fe-deficiency on the coupled processes of carbon catabolism and adenosine triphosphate (ATP) production in cultures of the marine bacterium Pseudoalteromonas haloplanktis. In Fe-limited cells, Fe-dependent oxidative pathways of ATP production were downregulated, leading to an intracellular energy deficit. Thus, by altering carbon metabolism and energy acquisition of heterotrophic bacteria, Fe may affect the cycling of carbon in parts of the sea.
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Clocksin, Kate M. "Isolation and characterization of heterotrophic bacteria from Lake Hoare, McMurdo Dry Valleys, Antarctica /." Available to subscribers only, 2005. http://proquest.umi.com/pqdweb?did=1079660831&sid=1&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Thesis (M.S.)--Southern Illinois University Carbondale, 2005."Department of Molecular Biology, Microbiology and Biochemisty." Includes bibliographical references (leaves 48-54). Also available online.
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Owens, James Hudson. "DISINFECTION KINETICS FOR A CHLORINE-RESISTANT FRACTION OF INDIGENOUS HETEROTROPHIC PLATE COUNT BACTERIA IN OHIO RIVER WATER." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1029506971.
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Wang, Yingying. ""The unseen majority": heterotrophic bacteria in freshwater, more than just small and non-cultivable /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17894.
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Posacka, Anna. "Biogeochemical cycling of copper in the Northeast Pacific Ocean : role of marine heterotrophic bacteria." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/62937.
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Copper (Cu) is important in regulating microbial activity in the ocean, as it can act both as a limiting nutrient and a toxic inhibitor depending on its concentration. Yet, our knowledge of its biogeochemical cycle is limited in many oceanic regions including the subarctic Northeast (NE) Pacific, as is our knowledge of Cu nutrition in marine heterotrophic bacteria. To address this, I investigated Cu biogeochemical cycling along a coastal‒oceanic transect, Line P, in the subarctic NE Pacific (Chapter 2). I also explored physiological responses to varying Cu availability (limiting to sufficient) of taxonomically diverse heterotrophic bacteria, which include isolates from surface waters of the Line P transect (Flavobacteriia member: Dokdonia sp. Dokd-P16, and Gammaproteobacteria members Pseudoalteromonas sp. strain PAlt-P2 [coastal] and PAlt-P26 [oceanic]), and a member of the marine Roseobacter clade within class Alphaproteobacteria (Ruegeria pomeroyi DSS-3). Several important processes were identified to moderate dissolved Cu along Line P. These include fluvial and sedimentary inputs (near the coast), upwelling of deep, Cu-rich waters in the Alaskan gyre (offshore), atmospheric inputs (offshore), as well as scavenging within the intermediate waters of the Oxygen Minimum Zone (OMZ) across the transect. Bacterial responses to changing Cu availability were diverse. Flavobacteriia member Dokd-P16 reduced its growth rate, carbon metabolism, and Cu quota (Cu:P) under Cu limitation, but enhanced its Mn quota. In contrast, both Pseudoalteromonas spp. were mostly unaffected by different Cu levels. Ruegeria pomeroyi maintained constant growth rates but moderated quotas of several metals (under low Cu: decreased Cu and Co, but increased Mn and Fe quotas), and some aspects of its C metabolism. These findings illuminate on the role of Cu in shaping bacterial species composition in the ocean, and the bacterially-mediated cycles of carbon and bioactive metals (i.e. Fe, Zn, Mn, Co). Copper quotas of heterotrophic bacteria are similar to those of cultured marine phytoplankton. Estimates of Cu partitioning between these planktonic groups in the euphotic zone of the NE Pacific revealed that up to 50% of biogenic Cu could be associated with bacterial biomass. Therefore, marine heterotrophic bacteria should not be overlooked in studies of Cu biogeochemical cycling.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
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Tregoning, George Seibert. "Isolation and Characterization of Halophilic Heterotrophic Bacteria from Lake Vanda, McMurdo Dry Valleys, Antarctica." OpenSIUC, 2010. https://opensiuc.lib.siu.edu/theses/395.
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Lake Vanda is a meromictic, permanently ice-covered lake in the McMurdo Dry Valleys. The McMurdo Dry Valleys are a polar desert in Southern Victorialand Antarctica. This area experiences very little rainfall and very cold average temperatures, around –20°C. Lake Vanda has an unusual limnological profile, with a sharp physical and chemical gradient at about 60 m where the water transitions from cold, oxic, and fresh, to warm, hypersaline, and sulfidic; CaCl2 rather than NaCl is the dominant salt. Aerobic enrichment techniques were used to isolate what turned out to be several strains of a species of Chromohalobacter, a genus of the Gammaproteobacteria, from Lake Vanda deep waters, while targeted enrichments for anaerobic and spore-forming bacteria were negative. The isolates were characterized for their temperature and pH optima, carbon and nitrogen nutrition, and salt tolerance and requirements. The results showed the organisms to be obligately aerobic with a broad pH range (optima pH 7). The isolates used some sugars and organic acids but not alcohols or fatty acids for energy and cell carbon, and showed a moderate requirement for NaCl but no requirement for CaCl2, even though CaCl2 is the predominant salt in their environment.
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Countway, Peter Dylan. "Carbon Production and Growth Physiology of Heterotrophic Bacteria in a Subtropical Coral Reef Ecosystem." W&M ScholarWorks, 1999. https://scholarworks.wm.edu/etd/1539617745.
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Gazihan, Akoglu Ayse. "Temporal And Spatial Changes In The Abundance And Biomass Of Pico (heterotrophic Bacteria &." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613331/index.pdf.
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The eastern Mediterranean has been known as the most oligotrophic water body among the worlds oceans and as a result of limited nutrient inputs from terrestrial sources primary productivity and plankton succession are restricted by lack of nutrients especially by phosphorus and nitrogen. Within this domain, Mersin bay forms a so called hot spot (highly sensitive) area where a sharp contrast exists between the coastal area supplied by land-based nutrient sources and the nutrient limited open sea. Excess nutrient enrichment lead for eutrophication in the inner Mersin bay while altering the quality and quantity of flora from shore to offshore. Microorganisms are highly sensitive and profoundly affected by environmental disturbances and are widely used to assess the impact of environmental changes on ecosystem functioning. With this study, it is aimed to investigate responses of the smaller fractions of phytoplankton composed of heterotrophic bacteria, Synechococcus and flagellates to rapidly changing ambient biological, chemical and physical properties of shelf waters over an extended period between 2008 and 2010. Epiflourescence microscopy and image analysis setup were used to enumerate and measure size of cells for biomass estimates.
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Khunjar, Wendell O'Neil. "Elucidating Factors that Impact the Removal of Organic Microconstituents by Ammonia Oxidizing and Heterotrophic Bacteria." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/77303.
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Although wastewater treatment plants are a line of defense in minimizing indiscriminate output of microconstituents to natural waters, we do not possess a fundamental understanding of the mechanisms involved in microconstituent removal during wastewater treatment. With this in mind, experiments were designed to investigate the factors that can influence the fate of four microconstituents, carbamazepine (CBZ), 17alpha-ethinylestradiol (EE2), iopromide (IOP), and trimethoprim (TMP), during biological suspended culture treatment. Specifically, the role that various ecological members of biological treatment systems play in biotransforming these compounds was evaluated.
Sorption assays were performed with inactivated biomass samples (ammonia oxidizing bacteria (AOB), laboratory enriched heterotrophic cultures free of active nitrifiers with low (Ox⁻) or high (Ox⁺) oxygenase activity, and a nitrifying activated sludge (NAS) from a full-scale wastewater treatment plant) to determine whether partitioning dictates removal of individual microconstituents. No microconstituents sorbed to the AOB culture. Neither CBZ nor IOP sorbed to Ox⁻, Ox⁺ and NAS cultures; however, EE2 and TMP sorbed to the Ox⁻, Ox⁺ and NAS biomass. Sorption was positively influenced by the presence of exopolymeric substances (EPS) associated with the cultures. The protein content of EPS affected EE2 and TMP sorption more appreciably than the polysaccharide content of EPS.
Further experiments were performed to investigate microconstituent biodegradation by AOBs, Ox⁻ and Ox⁺ cultures. The influence of growth state and oxygenase activity on biotransformation by each culture was also evaluated. Results indicate that EE2 was the only microconstituent that was amenable to biotransformation by batch cultured AOB and heterotrophic cultures. EE2 was biotransformed but not mineralized by AOB chemostat and batch cultures. TMP was not transformed by AOB batch or chemostat cultures; however both EE2 and TMP were transformed by Ox⁻ and Ox⁺ chemostat cultures. Radiolabeled studies showed that EE2 was mineralized by this culture. Kinetically, AOBs dominated EE2 transformation to monohydroxylated metabolites; however, both Ox⁻ and Ox⁺ cultures further degraded and mineralized EE2 and metabolites generated by AOBs. These results indicate that biotransformation of EE2 by NAS may be limited by heterotrophic activity whereas TMP fate may be a function of heterotrophic activity only. Oxygenase activity did not limit EE2 or TMP biotransformation in chemostat cultures.
Subsequent experiments that were performed to identify the factors that influence heterotrophic degradation of EE2 and TMP indicated that the presence of readily biodegradable substrates slows EE2 and TMP biotransformation. The impact of slowly biodegradable substrates like EPS on EE2 and TMP degradation was unclear. These results suggest that EE2 and TMP are most amenable to biodegradation in bioreactors where endogenous conditions dominate.Ph. D.
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Krey, Whitney B. (Whitney Blair). "Siderophore production by heterotrophic bacterial isolates from the Costa Rica upwelling dome." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/43114.
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Thesis (S.M.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2008.Includes bibliographical references (p. 54-59).
(cont) An increased understanding of heterotrophic bacterial strategies for acquiring nutrients and trace elements is critical for elucidating their impact on biogeochemical cycling in the ocean. It is estimated that iron is a limiting nutrient for phytoplankton growth in over 30% of the open ocean, but still little is known about bacterial strategies for iron acquisition. Siderophore (Fe ligand) production by bacteria may play a major role in influencing the bioavailability of iron in the ocean. Despite the importance of siderophores in the environment, only limited information from a select group of bacteria is available. On a cruise through the Costa Rica Dome (CRD) upwelling region in July 2005, a library of 867 isolates from five depth profiles inside and outside of the dome was obtained and screened for siderophore production using the Chrome Azurol-S (CAS) assay. Phylogenetic affiliation of 134 isolates was determined by sequencing the 16s rDNA gene, and determined that gamma proteobacteria such as Alteromonas, Pseudoalteromonas, Halomonas, and Marinobacter dominated the collection, while alpha-proteobacteria such as Roseobacter were also represented. The isolates obtained from stations in the CRD showed greater siderophore-producing capabilities between 55m and 100m while strains isolated from outside the CRD had shallower peak (-8-35m) production. Functional group determination showed that hydroxamate production dominated from 50-150m, while hydroxamate and catechol production is roughly equal in shallower waters. By characterizing the siderophores produced by these isolates and determining the genetic make-up of the population, these findings further our understanding of how heterotrophic microbes affect biogeochemical processes and the competitive nature of nutrient acquisition.
by Whitney B. Krey.
S.M.
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Jordan, Elizabeth Mary. "Characterization and antibacterial properties of coastal aerobic heterotrophic bacteria from the People's Republic of China and Thailand." Thesis, Heriot-Watt University, 2006. http://hdl.handle.net/10399/183.
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Mondino, Lindsay Jean. "Isolation and characterization of cold-active heterotrophic bacteria from lakes Bonney and Vida, McMurdo Dry Valleys, Antarctica /." Available to subscribers only, 2008. http://proquest.umi.com/pqdweb?did=1650504141&sid=2&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Thesis (M.S.)--Southern Illinois University Carbondale, 2008."Department of Molecular Biology, Microbiology and Biochemisty." Includes bibliographical references (p. 48-51). Also available online.
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Muthusamy, Saraladevi. "Functional Profiling Of Metabolic Regulation In Marine Bacteria." Doctoral thesis, Linnéuniversitetet, Institutionen för biologi och miljö (BOM), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-58257.
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Oceans are powered by active, metabolically diverse microorganisms, which are important in regulating biogeochemical cycles on Earth. Most of the ocean surface is often limited by nutrients, influencing bacterial growth and activities. Bacterial adaptation to fluctuating environmental conditions involves extensive reprogramming, and redirection of bacterial metabolism and physiology. In this thesis, I investigated the molecular mechanisms of bacterial adaptation strategies to sustain their growth and survival, focusing on the regulation of gene and protein expression in heterotrophic marine bacteria. Comparative proteomics analyses of the growth and non-growth conditions, uncovered central adaptations that marine bacteria employ to allow them to change their metabolism to support exponential growth in response to nutrients and to readjust to stationary phase under nutrient limitation. Our results highlight that during nutrient rich conditions three distinct bacteria lineages have great similarities in their proteome. On the other hand, we observed pronounced differences in behavior between taxa during stationary phase. Analyses of the proteorhodopsin containing bacterium Vibrio sp. AND4 during starvation showed that significantly improved survival in the light compared to darkness. Notably, proteins involved in promoting cell vitality and survival had higher relative abundance under light. In contrast, cells in the dark need to degrade their endogenous resources to support their basic cellular demands under starvation. Thus, light strongly influences how PR-containing bacteria organize their molecular composition in response to starvation. Study of alternative energy generation metabolisms in the Alphaproteobacteria Phaeobacter sp. MED193 showed that the addition of thiosulfate enhanced the bacterial growth yields. Concomitantly, inorganic sulfur oxidation gene expression increased with thiosulfate compared to controls. Moreover, thiosulfate stimulated protein synthesis and anaplerotic CO2 fixation. These findings imply that this bacterium could use their lithotrophic potential to gain additional energy from sulfur oxidation for both improving their growth and survival. This thesis concludes that analyses in model organisms under defined growth conditions gives invaluable knowledge about the regulatory networks and physiological strategies that ensure the growth and survival of heterotrophic bacteria. This is critically important for interpreting bacterial responses to dynamic environmental changes. Moreover, these analyses are crucial for understanding genetic and proteomic responses in microbial communities or uncultivated organisms in terms of defining ecological niches of planktonic bacteria
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Goudie, E. Dwayne. "Characterization of bacteria from the sediment-water interface of Newfoundland coastal waters using patterns of carbon source utilization." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0024/MQ36127.pdf.
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Ghosh, Suchismita. "Utilization of different forms of nitrogen by heterotrophic bacteria under varying organic carbon concentrations| From isolates to communities." Thesis, Kent State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3618890.
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It is important to understand fate of nutrients like nitrogen, in streams given that anthropogenic activity, such as agriculture, have increased inputs of biologically reactive nitrogen to the environment leading to deterioration of stream health and eutrophication. Bacteria play a crucial role in the driving essential biogeochemical transformations. The purpose of this research was to improve our understanding of organic and inorganic nitrogen utilization by bacterial isolates and complex bacterial communities. Role of bacterial diversity in resource utilization is mostly neglected in biogeochemical models. Identification of bacteria based on molecular methods, like 16S rDNA sequencing, yield a wealth of information related to prokaryotic diversity and its importance in driving essential biogeochemical cycles. In this research utilization of organic and inorganic forms of nitrogen by stream heterotrophic bacterial isolates were examined. Our results reveal differences in bacterial resource utilization not as a function of the different taxa involved but of the enrichments the isolates were obtained from, as immediate environment dictate bacterial response to different nutrients and exerts a selection pressure. Carbon availability also influences nitrogen dynamics. To examine the impact of carbon on bacterial uptake of organic and inorganic nitrogen, bacterial abundance and community composition were examined in controlled, laboratory microcosms. There was a strong influence of carbon availability on bacterial nitrogen utilization, with preferential uptake of organic forms under low carbon concentrations. Carbon and nitrogen treatments likely drove changes in bacterial community composition that, in turn, affected rates of nitrogen utilization under various carbon concentrations. Metabolic functions, such as particular biogeochemical reactions are catalyzed by microbial extracellular enzymes, which are likely linked to the constituting taxa in a given microbial community. This study tracked temporal patterns of bacterial community structure and potential microbial enzyme activities in response to seasonal changes in stream organic matter pool. Differences in enzyme activities were highly correlated to nutrient (carbon and nitrogen) availability while differences in bacterial community structure were mostly driven by environmental conditions. However, the absence of link between bacterial community structure and potential enzyme activity is indicative of functional redundancy within microbial communities.
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Hosie, Arthur Hugh Frank. "The application of molecular techniques to investigate the production of sodium channel blocking toxins by heterotrophic marine bacteria." Thesis, University of Glasgow, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298068.
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Ghosh, Suchismita. "UTILIZATION OF DIFFERENT FORMS OF NITROGEN BY HETEROTROPHIC BACTERIA UNDER VARYING ORGANIC CARBON CONCENTRATIONS: FROM ISOLATES TO COMMUNITIES." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1374844259.
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Shivaji, Sangeetha. "Functional analysis of a modC homolog in the Azotobacter vinelandii nif-gene cluster." Master's thesis, Mississippi State : Mississippi State University, 2008. http://library.msstate.edu/etd/show.asp?etd=etd-11052008-165140.
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Stine, William S. "Survival of enteric pathogens on the surface of fresh produce and intake of heterotrophic bacteria in the United States." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280656.
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Disease due to the consumption of food contaminated with enteric microorganisms has been well established. The first study described in this dissertation was designed to determine the effect of relative humidity on the pre-harvest survival of enteric pathogens on the surfaces of fresh produce. Additionally, Clostridium perfringens was evaluated as an indicator of fecal contamination on fresh produce. Pathogenic and surrogate microorganisms, including Escherichia coli O157:H7, Escherichia coli ATCC 25922, Salmonella enterica subsp. enterica, Shigella sonnei, C. perfringens, coliphage PRD1, feline calicivirus (FCV), and hepatitis A virus (HAV), were inoculated onto the surfaces of cantaloupe, iceberg lettuce, and bell peppers. Experiments were conducted in a controlled environment chamber. Survival of microorganisms on the produce surfaces was not uniformly affected by relative humidity. However, due to the survival of all microorganisms at least 14 days in at least one experiment, measures should be taken to lessen the exposure of produce to fecal contamination as harvest time approaches. C. perfringens survived longer than all other bacteria and feline calicivirus in all experiments, with the exception of E. coli O157:H7 and S. enterica subsp. enterica on lettuce. This trend suggests that C. perfringens may be an acceptable indicator of bacterial contamination and survival in various environments and on different types of crops. The second study was conducted to determine the intake of heterotrophic bacteria by the average person in the United States from food and water. A literature review was conducted to determine the concentration of heterotrophic plate count (HPC) bacteria in foods and water from the household tap. Food items from grocery stores and fast food restaurants in Tucson, AZ were also evaluated for HPC bacteria. It was determined that in the United States, 0.048 to 4.5% of the typical consumer's HPC bacteria intake is derived from water consumed from the household tap. Therefore, HPC bacteria in tap water do not represent a significant source of the total HPC bacteria consumed in the average diet of individuals in the United States.
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Carranza, Muñoz Andrea. "Mainstream Deammonification process monitoring by bacterial activity tests." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-281698.
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Deammonification is a widely used technology for side stream treatment with rich ammonium streams at relatively high temperatures, such as, the reject water coming from dewatering units in treatment of digested sludge and industrial wastewaters. The deammonification process has lower operational costs than conventional systems, consumes less energy, enables the increase of biogas production and it is easy to implement. However, this technology has not yet been applied in full- scale mainstream treatment due to its restrictions in coping with high C/N ratios, low temperatures, and the need for post-treatment processes. These conditions are allegedly negative to the growth and performance of anammox bacteria affecting the bacterial groups’ behavior in the process. This master thesis project aimed to evaluate the feasibility of using deammonification to remove nitrogen from mainstream wastewater, which was studied by monitoring the bacterial activity in a pilot scale reactor. The different bacterial groups involved (AOB, NOB, heterotrophs, and denitrifiers) were monitored by weekly measuring their activity in batch activity tests. The results allowed the evaluation of different operational scenarios and their impact by following up on the changes in the bacterial competition. The study was conducted for six months in a single-stage IFAS (integrated fixed-film activated sludge) pilot-scale reactor located in Stockholm and fed with pretreated (with a UASB) municipal wastewater. The different operational scenarios involved changes in temperature, aeration patterns, DO concentration, SRT, and HRT. The adjustment of these features was done in the interest of promoting AOB and anammox bacterial growth, leading to an improvement of the deammonification efficiency in future studies. However, the chosen operational conditions were to enhance bacterial competition and facilitate its visualization, not to maximize nitrogen removal. Thus, the most suitable scenario found during this study included DO concentration of 1.5 mg/L with 10 aeration-20 non-aeration pattern and ensured nitrogen removal rates within normal values while allowing the monitoring of all the bacterial groups. TN removal reached a value above 50% and NH4-N above 95%, whereas nitrogen Removal Rate (NRR) increased to 30g/N/m3-d and the system had an overall nitrogen removal efficiency of 75%. Nevertheless, it was proven that in the right environment, the necessary bacterial groups can be selectively accumulated and successfully perform deammonification and reduce nitrogen levels in mainstream wastewater.Deammonifikation är en välanvänd teknik för rening av sidoströmmar med höga ammoniumkoncentrationer vid relativt hög temperatur, som till exempel rejektvatten från avvattning av rötslam eller industriellt avloppsvatten. Deammonifikationsprocessen har lägre driftkostnad än konventionella reningsprocesser, förbrukar mindre energi samt möjliggör högre biogasproduktion samtidigt som processen är enkel att implementera. Reningstekniken har dock ännu inte tillämpats i fullskala för rening av huvudströmmen på grund av den höga C/N-kvoten och de låga vattentemperaturerna i kommunalt avloppsvatten samt behovet av efterbehandling. Detta anses ha en negativ inverkan på anammoxbakteriernas tillväxthastighet och funktion vilket påverkar bakteriegruppens beteende i processen. Syftet med detta examensarbete var att utvärdera om det är praktiskt genomförbart att använda deammonifikation för att rena kväve från kommunalt avloppsvatten, vilket följdes upp genom att studera bakterieaktiviteten i en pilotskalereaktor. De involverade bakteriegrupperna (AOB, NOB, heterotrofer och denitrifierare) övervakades genom att mäta den mikrobiella aktiviteten varje vecka med hjälp av batch-tester. Resultaten användes till att utvärdera olika driftstrategier och deras effekt genom att följa förändringarna i mikrobiell aktivitet hos de konkurrerande bakteriegrupperna. Studien genomfördes i Stockholm under sex månader i en enstegs-IFAS-pilotskalereaktor (integrerad process med biofilm på fast bärarmaterial och aktivslam) som matades med kommunalt avloppsvatten som förbehandlats i en UASB-reaktor. De olika driftstrategierna omfattade olika temperaturer, luftningsstrategier, syrekoncentrationer, slamåldrar och hydrauliska uppehållstider. Syftet med driftstrategierna var att främja AOB- och anammoxbakteriers tillväxt för att i framtida studier kunna erhålla en förbättrad deammonifikationsprocess. Syftet i denna studie var dock i första hand att förbättra den bakteriella konkurrensen och göra den lättare att mäta, inte att uppnå bästa möjliga kväverening. Den driftstrategi som gav bäst resultat i denna studie innebar att hålla en syrehalt på 1,5 mg/l med 10 minuter luftning följt av 20 minuter utan luftning vilket säkerställde en normal kväveavskiljning och samtidigt möjliggjorde övervakning av samtliga fyra bakteriegrupper. Totalkväveavskiljningen var över 50 % och ammoniumavskiljningen över 95 % medan kvävereningsaktiviteten ökade till 30 g N/m3-d och systemet hade en övergripande effektivitet på 75 %. Studien visade att under rätt förutsättningar kan de nödvändiga bakteriegrupperna selekteras fram och deammonifikation av kommunalt avloppsvatten kan utföras på ett framgångsrikt sätt.
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Koedooder, Coco. "The interplay between Fe-limitation, carbon and light in a (photo)heterotrophic bacterium." Electronic Thesis or Diss., Sorbonne université, 2019. http://www.theses.fr/2019SORUS170.
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Le fer (Fe) est un élément essentiel de la croissance microbienne marine, mais est présent sous forme de trace dans les eaux de surface des océans. Chez les bactéries hétérotrophes, la limitation en Fe affecte particulièrement la production d'ATP et il a été démontré que les bactéries appliquent diverses stratégies pour faire face à la présence de limitation en Fe. Les outils génétiques nous ont permis de tester deux stratégies potentielles au sein de l'organisme modèle Photobacterium angustum S14. Le shunt glyoxylique, une voie métabolique trouvée dans les bactéries aérobies contournant plusieurs étapes de TCA, s’est révélée être régulée à la hausse sous une limitation en Fe et nous proposons que la dérivation du shunt glyoxylique réoriente le métabolisme cellulaire de la chaîne de transport d’électrons, augmentant de ce fait l'efficacité métabolique de la cellule soumise à la limitation en Fe. La protéorhodopsine, une pompe à protons activée par la lumière trouvée dans plusieurs bactéries hétérotrophes, peut atténuer le stress lié au Fe si le gradient de proton produit est couplé à l'ATP synthase. Nos résultats ont montré que la protéorhodopsine augmentait à mesure que les cellules approchaient de la phase stationnaire dans des conditions à la fois remplies de Fe et limitant en Fe, mais étaient absentes pendant la phase exponentielle. Les travaux futurs visant à élucider le rôle de la protéorhodopsine, et en particulier en ce qui concerne la limitation du Fe, devraient donc être axés sur la phase stationnaire d'une cellule bactérienne. Les résultats de ce manuscrit de thèse ont contribué à la littérature actuelle sur la polyvalence des bactéries marines hétérotrophes pour faire face à la limitation en Fe et le rôle de la protéorhodopsine et du shunt glyoxylique dans l'environnement marinIron (Fe) is an essential element for marine microbial growth but is present in trace amounts in the surface waters of the ocean. In heterotrophic bacteria, Fe-limitation particularly impacts ATP production and have been shown to implement various strategies to cope in the presence of Fe-limitation. Genetic tools enabled us to test two potential strategies within the model organism Photobacterium angustum S14. The glyoxylate shunt, a metabolic pathway found in aerobic bacteria bypassing several steps within the classic tricarboxylic acid (TCA) was shown to be upregulated under Fe-limitation and we propose that the glyoxylate shunt was able to redirect a cell’s metabolism away from Fe-limiting steps within the electron transport, thereby increasing the metabolic efficiency of the cell under Fe-limitation. Proteorhodopsin, a light activated proton pump found in several heterotrophic bacteria, could alleviate Fe-stress if the produced proton gradient is coupled to ATP synthase. Our results showed that proteorhodopsin is upregulated as cells approached the stationary phase under both Fe-replete and Fe-limiting conditions but was absent during the exponential phase. Future work in elucidating the role of proteorhodopsin, and particularly under Fe-limitation, should therefore focus on the stationary phase of a bacterial cell. The results from this thesis manuscript contributed to a culminating body of work surrounding the versatility of marine heterotrophic bacteria in coping with Fe-limitation and is an appropriate addition to the literature surrounding the role of proteorhodopsin and the glyoxylate shunt within the marine environment
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Drakare, Stina. "The Role of Picophytoplankton in Lake Food Webs." Doctoral thesis, Uppsala University, Limnology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-2710.
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Picophytoplankton were inferior competitors for inorganic phosphorus compared to heterotrophic bacteria. This may be due to the source of energy available for the heterotrophs, while cell-size was of minor importance. However, picophytoplankton were superior to large phytoplankton in the competition for nutrients at low concentrations.
Biomass of picophytoplankton was low in brownwater lakes and high in clearwater lakes, compared to the biomass of heterotrophic bacteria. The results suggest that picophytoplankton are inferior to heterotrophic bacteria in the competition for inorganic nutrients in brownwater lakes, where the production of heterotrophic bacteria is subsidized by humic dissolved organic carbon (DOC)
Relative to large phytoplankton, picophytoplankton were most important in lakes with intermediate water colour, despite the fact that the lowest nutrient concentrations were found in the clearwater lakes. Large phytoplankton in the clearwater lakes may be able to overcome nutrient competition with picophytoplankton by vertical migration.
In conclusion, changes in nutrient content, light availability and concentrations of DOC affect the interactions of heterotrophic bacteria, picophytoplankton and large phytoplankton and are therefore important factors for the structure of the food web in the pelagic zones of lakes.
Picophytoplankton (planktonic algae and cyanobacteria, < 2 µm) constitute an important component of pelagic food webs. They are linked to larger phytoplankton and heterotrophic bacteria through complex interactions including competition, commensalism and predation. In this thesis, field and laboratory studies on the competitive ability of picophytoplankton are reported.
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Tebaldi, Roberta. "Avaliação bacteriológica de águas minerais sem gás e gaseificadas artificialmente comercializadas em garrafs individuais /." Araraquara : [s.n.], 2010. http://hdl.handle.net/11449/98433.
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Orientador: Adalberto Farache FilhoBanca: Clóvis Wesley Oliveira de Souza
Banca: João Bosco Faria
Resumo: A constante preocupação com a qualidade da água destinada ao consumo, a presença de sabores e odores desagradáveis decorrentes da adição de flúor e cloro nas águas de abastecimento público e a falta de suprimentos adequados de água potável, tem provocado uma contínua demanda por água mineral. A relativa escassez de estudos envolvendo a qualidade microbiológica da água mineral, principalmente na água mineral gaseificada artificialmente, gerou esta pesquisa que tem por objetivo, avaliar e comparar a qualidade bacteriológica de águas minerais sem gás e gaseificadas artificialmente, em embalagens descartáveis, de oito marcas comercializadas em supermercados das cidades de Ribeirão Preto e Araraquara - SP. As duzentos e quarenta amostras analisadas foram divididas em três lotes com cinco unidades gaseificadas e cinco sem gás de cada marca. Foram realizadas análises para determinação de bactérias do grupo coliforme, bactérias heterotróficas e Pseudomonas aeruginosa. Para análise de coliformes totais e E. coli utilizou-se a técnica de substratos cromogênicos, para Pseudomonas aeruginosa utilizou-se a técnica de tubos múltiplos específica e para contagem de bactérias heterotróficas foi utilizada a técnica de cultivo em profundidade. Para as cento e vinte amostras não gaseificadas analisadas (100%), verificou-se a presença de coliformes totais em oito amostras (6,67%), presença de E. coli em seis amostras (5%), presença de Pseudomonas aeruginosa em cinco amostras (4,2%), e 102 amostras (85%) apresentaram contagem de bactérias heterotróficas maior que 500 UFC/mL. Para as cento e vinte amostras gaseificadas analisadas verificou-se que nenhuma delas apresentou contaminações para o grupo coliforme (totais e E. coli) e para Pseudomonas aeruginosa. Apenas três amostras (2,5%) apresentaram contagens superiores a 500 UFC/mL para bactérias heterotróficas... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The constant concern with the water quality reserved to human consumption, the presence of tastes and odors caused by the addition of fluoride and chlorine in public water supplies and the destitution of adequate supplies of potable water has challenged a continuous demand for mineral water. The relative privation of studies on the bacteriological quality of mineral water, mainly in artificially carbonated mineral water generated this project that purpose to value and to compare the microbiological quality of mineral water without gas and carbonated artificially, in dismissible tacking, of eight types, sold in supermarkets in the cities of Araraquara/SP and Ribeirão Preto/SP. The two hundred forty analyzed samples were divided in shares with five unities carbonated mineral water and five without gas. There were put into practice analysis for determination of coliform bacteria, heterotrophic bacteria and Pseudomonas aeruginosa. To analysis of total coliform and E. coli it was used the chromogenic substrates technique, for Pseudomonas aeruginosa used the multiple tube specific technique and to counting heterotrophic bacteria, it was used the technique of growing in depth. To the one hundred twenty samples no carbonated water analyzed (100%), was checked the presence of total coliforms in eight samples (6,67%), presence of E. coli in six samples (5%), presence of Pseudomonas aeruginosa in five samples (4,2%), and one hundred two samples (85%) was with counts above 500 CFU/mL for heterotrophic bacteria. To the one hundred twenty carbonated water samples analyzed (100%), was checked that no samples analyzed was contaminated to the coliform group (total and E. coli) and to Pseudomonas aeruginosa. Just three samples (2,5%) present counts above 500 CFU/mL for heterotrophic bacteria. All the brands of the samples no carbonated water tested (100%) presents out of the specifications of Brazilian legislation in one or more parameters analyzed
Mestre
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Farnelid, Hanna. "Distribution and activity of nitrogen-fixing bacteria in marine and estuarine waters." Doctoral thesis, Linnéuniversitetet, Institutionen för naturvetenskap, NV, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:polar:diva-1814.
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In aquatic environments the availability of nitrogen (N) generally limits primary production. N2-fixing prokaryotes (diazotrophs) can convert N2 gas into ammonium and provide significant input of N into the oceans. Cyanobacteria are thought to be the main N2-fixers but diazotrophs also include a wide range of heterotrophic bacteria. However, their activity and regulation in the water column is largely unknown. In this thesis the distribution, diversity, abundance, and activity of marine and estuarine heterotrophic diazotrophs was investigated. With molecular methods targeting the nifH gene, encoding the nitrogenase enzyme for N2 fixation, it was shown that diverse nifH genes affiliating with heterotrophic bacteria were ubiquitous in surface waters from ten marine locations world-wide and the estuarine Baltic Sea. Through enrichment cultures of Baltic Sea surface water in anaerobic N-free medium, heterotrophic N2 fixation was induced showing that there was a functional N2-fixing community present and isolates of heterotrophic diazotrophs were obtained. In Sargasso Sea surface waters, transcripts of nifH related to heterotrophic bacteria were detected indicating heterotrophic N2-fixing activity. Nitrogenase expression is thought to be highly regulated by the availability of inorganic N and the presence of oxygen. Low oxygen zones within the water column can be found in association with plankton. The presence of diazotrophs as symbionts of heterotrophic dinoflagellates was investigated and nifH genes related to heterotrophic diazotrophs rather than the cyanobacterial symbionts were found, suggesting that a symbiotic co-existence prevailed. Oxic-anoxic interfaces could also be potential sites for heterotrophic N2 fixation. The Baltic Sea contains large areas of anoxic bottom water. At the chemocline and in anoxic deep water heterotrophic diazotrophs were diverse, abundant and active. These findings extend the currently known regime of N2 fixation to also include ammonium-rich anaerobic waters. The results of this thesis suggest that heterotrophic diazotrophs are diverse and widely distributed in marine and estuarine waters and that they can also be active. However, limits in the knowledge on their physiology and factors which regulate their N2 fixation activity currently prevent an evaluation of their importance in the global marine N budget.
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Samek, Michaela. "The community structure of heterotrophic and autotrophic bacteria and microflagellates in four lakes of the Precambrian Shield and the possible roles of bacteria in mercury dynamics in freshwater systems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq23486.pdf.
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Sander, Bettina Christa. "Benthic bacterial production in Eastern Townships and Laurentian lakes." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=69681.
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The $ sp3$H thymidine incorporation (TTI) method has been frequently used to estimate benthic bacterial production rates in well oxygenated marine and river sediments, but not in the frequently more reduced lake sediments. In chapter 1, I evaluate the published sediment production literature and examine useful predictors of in situ bacterial production in mostly marine and riverine sediments. In chapters 2 and 3, I estimated and compared benthic production rates by TTI, frequency of dividing cells (FDC), the dilution method (DIL) and sediment respiration (SR) in 13 Quebec lakes to assess the reliability of the TTI based production rates. The TTI method was first calibrated, but despite keeping incubation times short and at in situ temperature, using optimal sediment volumes to saturate $ sp3$H thymidine (TdR) uptake rates, and correcting production rates for $ sp3$H-DNA recovery efficiencies, only a maximum of 10% of $ sp3$H TdR was incorporated into DNA and only extracellular isotope dilution could be accounted for (chapter 2). Most problematic, however, is the increasing presence of active bacteria unable to take up and incorporate TdR as lake sediments become more reduced (chapter 3). TTI based results are also not nearly as well correlated to environmental factors as those obtained from SR. (Abstract shortened by UMI.)
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Avci, Burak [Verfasser], Rudolf [Akademischer Betreuer] Amann, Rudolf [Gutachter] Amann, and Thorsten [Gutachter] Brinkhoff. "Niches of abundant heterotrophic bacteria during North Sea spring algal blooms / Burak Avci ; Gutachter: Rudolf Amann, Thorsten Brinkhoff ; Betreuer: Rudolf Amann." Bremen : Staats- und Universitätsbibliothek Bremen, 2018. http://d-nb.info/1176103458/34.
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Bhedi, Chinmayee D. "Quorum Sensing Signals Produced by Heterotrophic Bacteria in Black Band Disease (BBD) of Corals and Their Potential Role in BBD Pathogenesis." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3367.
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Black band disease (BBD) of corals is a temperature dependent, highly virulent, polymicrobial disease affecting reef-building corals globally. The microbial consortium of BBD is primarily comprised of functional physiological groups that include photosynthetic cyanobacteria, sulfate reducers, sulfide oxidizers and a vast repertoire of heterotrophic bacteria. Quorum sensing (QS), the cell-density dependent communication phenomenon in bacteria, is known to induce expression of genes for a variety of virulence factors in diseases worldwide. Microbes capable of QS release signals such as acyl homoserine lactones (AHLs) and autoinducer-2 (AI-2), which coordinate microbial interaction. The focus of the present study was to investigate the presence and potential role of QS in BBD pathogenicity, utilizing culture dependent and independent methodologies. Isolates across coral health states including BBD, were screened for production of QS signals, and AHL and AI-2 production capabilities were analyzed via LC-MS/MS. The effect of temperature on AHLs was also examined. Additionally, antimicrobial production capabilities of isolates were tested. BBD metagenomes were utilized to screen for sequences related to QS, antimicrobial synthesis, and antimicrobial resistance genes. BBD isolates represented a significantly higher proportion of isolates capable of producing QS signals in comparison to healthy coral isolates. Several AHLs produced by coral derived bacterial cultures were identified, and three AHLs, specifically 3OHC4, 3OHC5 and 3OHC6, showed a significant increase in production at an elevated temperature of 30 °C, which correlates with increased BBD incidence on reefs with increasing water temperature. Most of the BBD cultured isolates were identified as vibrios. Several sequences related to QS, antimicrobial synthesis and resistance genes were detected in the BBD metagenomes. Based on the findings of this study, a model for potential microbial interactions amongst BBD heterotrophs, centered around QS, is proposed. Taken together, the findings from this study provide a clearer understanding of the potential role of QS in BBD, and serve as the basis for further studies aimed at elucidating the pathogenesis of an intricate coral disease.
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Kassotaki, Elissavet. "Elimination of micropollutants in conventional and novel nitrogen removal processes. A comparative assessment of diverse microbial communities capabilities." Doctoral thesis, Universitat de Girona, 2018. http://hdl.handle.net/10803/664342.
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Pharmaceutically active compounds (PhACs) and endocrine disrupting compounds (EDCs) can pose a significant risk to the environment and human health, undermining prosperity. Current wastewater treatment plants (WWTPs) cannot efficiently act as barriers to their release and have been identified as main points of discharge and contamination. The present thesis aimed to investigate the fate of five PhACs (ibuprofen, sulfamethoxazole, metoprolol, carbamazepine and venlafaxine) and five EDCs (estrone, 17β-estradiol, estriol, 17α-ethinylestradiol and bisphenol A) in different systems simulating wastewater treatment scenarios and to identify factors triggering their elimination. A comparative assessment was carried out to determine the contribution of the microbial groups (either autotrophic or heterotrophic) present in different lab, pilot and full-scale treatment systems performing different processes in the removal of the selected compounds. The results indicated that the overall efficiency of wastewater treatment systems can be broadened by combining different aerobic and anaerobic conditions and different types of biomassEls compostos farmacèuticament actius (PhACs) i els pertorbadors endocrins(EDC) poden suposar un risc considerable per al medi ambient i la salut humana. Les estacions depuradores d'aigües residuals (EDAR) no poden actuar de manera eficient com a barreres per al seu alliberament i s'han identificat com a punts principals de descàrrega. La present tesi pretén determinar el destí de cinc PhACs (ibuprofèn, sulfametoxazol, metoprolol, carbamazepina i venlafaxina) i cinc EDCs (estrona, 17β-estradiol, estriol, 17α-etinilestradiol i bisfenol A), en sistemes que simulen escenaris de tractament d'aigües residuals, per identificar els factors claus en la seva eliminació. Es va realitzar una avaluació comparativa per determinar la contribució dels diferents grups bacterians (autòtrofs o heteròtrofs) presents en diferents sistemes a escala de laboratori, pilot i a gran escala. Els resultats indiquen que l'eficiència global dels sistemes de tractament d'aigües residuals es pot ampliar combinant diferents condicions aeròbiques i anaeròbies i tipus de biomassa
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Walter, Sunette. "Characterization of heterotrophic plate count (HPC) bacteria from biofilm and bulk water samples from the Potchefstroom drinking water distribution system / by S. Walter." Thesis, North-West University, 2009. http://hdl.handle.net/10394/4977.
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The presence of heterotrophic plate count (HPC) bacteria in drinking water distribution systems is usually not considered harmful to the general consumer. However, precautions must be taken regarding the immunocompromised. All water supply authorities in South Africa are lawfully required to provide consumers with high-quality drinking water that complies with South African-and international standards. This study mainly focused on the isolation, identification and characterization of HPC and other bacteria from biofilm-and bulk water samples from two sampling points located within the Potchefstroom drinking water distribution system. Based on five main objectives set out in this study, results indicated that the bulk water at the J.S. van der Merwe building was of ideal quality fit for lifetime consumption. Application of enrichment-and selective media allowed for the isolation of 12 different bacterial morphotypes. These were identified by way of biochemical-and molecular methods as Bacillus cereus, Bacillus subtilis, Brevundimonas spp., Clostridiaceae, Corynebacterium renale, Flavobacteriaceae, Kytococcus sedentarius, Leuconostoc lactic, Lysinibacillus sphaericus, Pseudomonas spp., Staphylococcus aureus and Staphylococcus capitis. The greatest diversity of bacteria was detected early autumn 2008, while the lowest diversity occurred during mid-winter 2007. Bacillus cereus, Kytococcus sedentarius and Staphylococcus capitis displayed potential pathogenic properties on blood agar. Kytococcus sedentarius could be classified as potentially the most pathogenic among the isolates. All isolates displayed multiple-resistant patterns towards tested antibiotics. Corynebacterium renale and Staphylococcus aureus were least resistant bacterial species and Lysinibacillus sphaericus the most resistant. All isolates were susceptible to ciprofloxacin (CIP) and streptomycin (S), but most were resistant to erythromycin (E). Transmission electron microscopy (TEM) allowed for detailed examination of Brevundimonas spp., Pseudomonas spp. and Staphylococcus spp. The capability of Brevundimonas spp. to produce slime and store nutrients within inclusion bodies, suggests the ability of this bacterium to form biofilm and persist in the drinking water for prolonged periods. Despite the inhibitory or toxic effect of copper against bacterial growth, scanning electron microscopy (SEM) revealed the presence of biofilms as well as diatoms on red-copper coupons. Biofilm activity was also observed on reverse-osmosis (RO) filters. Since corrosion was evident on red-copper coupons, it is recommended that prospective studies also look into the significance of microbial induced corrosion (MIC) within the Potchefstroom drinking water distribution system. Other prospects include determining minimum inhibitory concentrations of isolates against antibiotics and the application of culture independent methods such as SSCP and DGGE to investigate biofilm development. The use of diatoms as an index of the drinking water quality is also suggested.Thesis (M.Sc. (Environmental Science))--North-West University, Potchefstroom Campus, 2010.
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Vos, Elsie Petronella. "Investigation of the levels and diversity of heterotrophic bacteria in drinking water biofilms of Potchefstroom, North-West Province, RSA / by Elsie Petronella Vos." Thesis, North-West University, 2007. http://hdl.handle.net/10394/2041.
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