Dissertations / Theses on the topic 'Applied microbiology'
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Dabdoub, Shareef Majed. "Applied Visual Analytics in Molecular, Cellular, and Microbiology." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1322602183.
Full textIker, Brandon Charles. "Application of Advanced Molecular Techniques in Applied Environmental Microbiology." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/301699.
Full textCastro, Lilian Cristina Menegon. "Avaliação de indicadores biológicos na validação de processos de esterilização de isoladores por peróxido de hidrogênio." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-14062016-184137/.
Full textThe resistance of tive microrganisms found in the sterile production area (Crystallization Area) flora was tested against the hydrogen peroxide gas and the D value of each microrganism was compared to the Bacillus stearothermophilus D Value ATCC 12980 exposed to the same agent. The microrganisms tested were Bacillus sp, M. luteus, Corynebacterium, Staphylococcus sp e Penicillium sp. The purpose of this test was to prove that the resistance of Bacillus stearothermophilus against the exposition the hydrogen peroxide is higher when compared to others microrganisms found in the production area. The methodology consisted in inoculating 0.01 mL of microrganisms suspension with 102UFC/0,01 mL count in stainless steel coupons, treated previously with dry heat and further exposition to the hydrogen peroxide. The experiment demonstrated that the Bacillus stearothermophilus D value is higher against all others microrganisms tested proving that the use of this microrganism for the challenge is appropriate. It was also pertormed a test to guarantee that the stainless steel support is the most recommended one for this purpose, using supports of different materials normally found in the interior of the isolators (PVC, stainless steel, CKC, Teflon, polypropylene, latex, silicon, Hypalon, glass, nylon, aluminum foil) with 0,01 mL Bacillus stearothermophilus inoculum with the count of 102UFC/O,01 mL, that was properly veritied.
Lennox, Samuel David. "The applied mathematical modelling of milk and milk solids production." Thesis, Queen's University Belfast, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317476.
Full textMalactos, Michael D. "Investigations into the detection of injured Salmonella typhimurium in foodstuffs." Thesis, University of Bedfordshire, 1998. http://hdl.handle.net/10547/336486.
Full textVila, Brugalla Montserrat. "Microbiological safety evaluation of sous-vide treatments at mild temperatures applied to pork loin." Doctoral thesis, Universitat Autònoma de Barcelona, 2019. http://hdl.handle.net/10803/667333.
Full textA raising interest has been detected nowadays in relation to the use of cooking techniques at moderate temperatures like sous-vide cooking. Given the possibility of using these techniques to prepare food in advance, and considering that data on behaviour of bacteria in the range of 40 to 60 °C is scarce, there is great concern in accurately define the microbiological safety of this food. The aim of this doctoral thesis was to characterize the effect of mild temperature vacuum cooking treatments on two main food pathogens, L. monocytogenes and Salmonella spp. inoculated in raw pork meat. Challenge studies were conducted using two bacterial strains of Salmonella (S. enterica subsp. enterica serovar Enteritidis CECT 4300 and Senftenberg CECT 4565), and Listeria monocytogenes (CECT 4031 and Scott A), inoculated either individually or in combination. Pork loin pieces were inoculated, vacuum packed and cooked in a steam oven at two different temperatures (55 and 60 ºC) during 30, 60 or 90 minutes. Lethality caused by each treatment was determined just after cooking. Further recovery of injured cells was evaluated during storage at 4 and 8 ºC until the 30th day after treatments. Evolution of microbial counts were modelled using the predictive tools Bioinactivation FE for thermal inactivation and DMFit for growth through the storage time. The Monte Carlo method was applied in order to incorporate the variability observed between replicates in the predictive models of inactivation and growth. The heterogeneity of results was important. One source of this variability was probably the steam oven performance between 55 and 60 ºC. At these cooking temperatures, Salmonella spp. was more heat resistant than L. monocytogenes, but it was less able to growth during cold storage. Microbiological safety evaluation of sous-vide mild heat treatments must be based both on lethality and on the capability of recovery during storage. Considering both factors, three different scenarios were obtained: complete inactivation, presence of viable cells and a growth/no growth interface. In case of a complete inactivation (S. Enteritidis and L. monocytogenes Scott A and CECT 4031 cooked at 60 ºC), inoculated strains were not detected in any replicate during all the storage period. In case of viability, all replicates showed counts above the quantification limit (5 CFU/g), whether growth was observed or not (S. Senftenberg, L. monocytogenes Scott A, cocktail of L. monocytogenes strains at 55 ºC, and cocktail of Salmonella spp. strains at 55 ºC during 30 min). Finally, in some experimental conditions a “growth/no growth” behaviour, with different proportions of death, viable and injured cells, was observed. This circumstance took place in inoculated samples cooked at 60 ºC (S. Senftenberg, cocktail of L. monocytogenes) and 55 ºC (cocktail of Salmonella spp. and L. monocytogenes CECT 4031). In conclusion, the microbiological safety of sous-vide mild heat processes have to be accurately assessed on a case-by-case basis. Heat treatments at 60 ºC for 90 min applied to pork loin could be considered reasonably safe and suitable for “cook-chill” systems in relation to Salmonella spp. and L. monocytogenes strains included in the essay, as long as no temperature abuse occurs during shelf-life. Treatments at 60 ºC during 30 and 60 minutes must be used only for “cook-serve” systems. Sous-vide cooking of pork loin at 55 ºC during 30, 60 and 90 minutes cannot be considered safe in relation to S. Senftenberg and L. monocytogenes Scott A due to the presence of survivor cells that can growth at 8 ºC. This treatment must be used only for “cook-serve” systems. This study provides useful data for future risk assessment studies applied to meat sous-vide cooked at mild temperatures.
Skipper, Philip. "Biodeterioration of limestone : role of bacterial biofilms and possible intervention strategies." Thesis, University of Lincoln, 2018. http://eprints.lincoln.ac.uk/33697/.
Full textReinert, Cristina. "Caracterização do cassete cromossômico estafilocócico mec (SCCmec) de cepas endêmicas nosocomiais de Staphylococcus aureus resistentes a oxacilina e vancomicina." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/9/9136/tde-16082017-164142/.
Full textThe types of SCCmec found in nosocomial methicillin-resistant Staphylococcus aureus (MRSA) strains can be designated type I, II or III. A novel type of SCCmec, designated type IV, was identified in strains isolated in outpatients. These strains, called community-acquired MRSA or CA-MRSA, do not contain antimicrobial resistance genes other than mecA, however, they are more virulent. In order to characterise the structural diversity of SCCmec in Brazilian MRSA strains, 50 MRSA strains were studied, including some vancomycin intermediate resistant S. aureus (VISA) and heterogeneous vancomycin intermediate S. aureus (HVISA) strains. All strains were isolated between 1995-2000, in hospitaIs in 13 Brazilian States, and belonged to different PFGE clones. Strains were analysed as to their susceptibility profile, RFLP of the coagulase gene, phagetype and SCCmec type. The majority of strains belonged to the Brazilian Endemic Clone, which carries an type IH SCCmec, which in turn, was also found in other PFGE clones. The type IV SCCmec was found in 3 strains (belonging to the J, L and D clones) and presented a susceptibility profile to a number of drugs of different antimicrobial classes. The type IV SCCmec is present among Brazilian MRSA strains and can be disseminated in the community and in hospitaIs throughout the country.
Visi, David K. "The Microbial Retting Environment of Hibiscus Cannabinus and Its Implications in Broader Applications." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc801953/.
Full textZimmermann, Ana Lucia Santos. "Desenvolvimento e avaliação de micropartículas contendo microrganismos viáveis utilizados como bioinseticida." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-09022015-103417/.
Full textThe aim of this work was to develop powder formulations containing microparticles, to be used as multiparticulate delivery systems. Two different methods were investigated : 1) the preparation of microparticles by spray drying using casein, hydroxyethylcellulose (HEC) and hydroxypropilmetilcellulose (HPMC) and 2) the preparation of calcium alginate and chitosan-alginate microparticles by using an atomizer device. Different experimental procedures to prepare calcium alginate and chitosanalginate microparticles were evaluated and variables beHeved to be important for the membrane formation were examined. The mean particles diarneter ranged from 60 to 553 µm. When a comparison was made between the surface morphology of calcium alginate and alginate-chitosan microparticles, remarkable roughness and more porous structure was observed in the chitosan-alginate microparticles. Some properties of the microparticles depended on the method and the procedure conditions of forming the chitosan-alginate complex. Calcium alginate and chitosan-alginate microparticles containing two different bioinsecticides were also prepared: 1) a spore/δ-endotoxinscomplex of Bacillus thuringiensis var.kurstaki (Btk) and 2) polyhedra of Baculovirus anticarsia (Bv), a viral insecticide. The results shown that the encapsulation of suspensions of Btk containing spore/toxin complex or polyhedra of B. anticarcia in calcium alginate and chitosan-alginate microparticles did not decrease the larvicidal activity of these biopesticides against lepidopterous pests. The formulations developed in this study remained unchanged, did not swell, did not release the spores (Btk) or the polyhedra (Bv), when dispersed in water and could be useful to be applied by aqueous spray as bioinsecticides in agriculture. On the other hand, casein, HEC and HPMC microparticles prepared by spray drying were not suitable to encapsulate bioinsecticides because they dissolved fastly after dispersion in water.
Barlow, Peter George. "The effects of air pollution particles on clearance mechanisms within the lung." Thesis, Edinburgh Napier University, 2004. http://researchrepository.napier.ac.uk/Output/1052591.
Full textCintra, Ana Carolina Suzuki Dias. "Alfa-oxidação de propionato está envolvida na redução da produção de plástico biodegradável em Burkholderia sacchari?" Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/42/42132/tde-19092008-104933/.
Full textBurkholderia sacchari is a new bacterial species from brazilian soil, able to grow in sucrose, accumulating intracellular granules of polyester belonging to the polyhydroxyalkanoate family (PHA). When cultivated on sucrose, the homopolymer poly-3-hydroxybutyrate is accumulated by this bacterium, which is used as biodegradable and biocompatible plastic. When sucrose and propionic acid are supplied as carbon sources, B. sacchari cells accumulate the copolymer poly-3-hydroxybutyrate-co-3-hydroxyvalerate (P3HB-co-3HV). However, a small percentage ofthe propionic acid supplied is converted to 3HV units, because efficient catabolic pathways convert this substrate preferentially to biomass, CO2 and water, thus reducing the efficiency of polymer production. At least two propionate catabolic pathways have been previously indicated in B. sacchari: a-oxidation and the 2-methylcitric acid (2MCC), the latter confirmed at molecular leveI. UV mutants previously obtained were unable to grow in propionate (prp) and also showed the phenotype affected concerning grow on intermediates of propionate a-oxidation. In the present work, after a screening in B. sacchari genomic libraries, one ofthem constructed also in the present work, the prp + phenotype was restored to the mutants by three different DNA fragments harbored by dones A), PI and P2. Quantitative experiments revealed that AI restored only partially the quantitative conversion of propionate to 3HV units to the mutants. PI restored the ability to grow in propionate and in other intermediates of a-oxidation to one prp mutant. A DNA 1.2 Kb subfragment of PI, still able to complement prp mutants, was subcloned and sequenced, showing similarity to DNA sequences encoding to LysR-type transcriptional regulators of various bacteria, including BlIrkholderia species. Adjacent regions to LysR in different genomes of BlIrkholderia are annotated as encoding to acyl-CoA dehydrogenases, neighboring a predicted acyl-CoA transferases/carnitine dehydratase and a permease ofthe major facilitator superfamily MFS-1. After confirmation ofthe same adjacent regions in B. sacchari and also their especific deletion, it will be possible to prove the presence of the pathway indicated here in the catabolism of propionate.
Silva, Carlos Henrique Domingues da. "Fungos associados a invertebrados marinhos: isolamento, seleção e avaliação da produção de enzimas celulolíticas." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-30092010-110051/.
Full textThe Marine mycology is a relatively recent and little is known about the diversity of its communities. Thus, the isolation, separation and preservation of fungi derived from the sea can lead to the discovery of new technologies. The aim of this study was the diversity of filamentous fungi isolates derived marine and select capable of producing cellulolytic enzymes. It had been selectively isolated filamentous fungi from samples of marine macro-organisms collected in 2007 and 2008. The results showed a wide range of potential cellulolytic fungi, belonging to the phylum Basidiomycota and Ascomycota. In the experiments to produce cellulases, 17 had satisfactory results of CMCase and FPase and were selected for evaluation of cellobiase. The enzyme kinetics experiments showed better results for the production of cellulases in a medium containing wheat bran. The work demonstrates the potential for biotechnological application of fungi and stimulate further research with cellulases.
Benitez, Maria Soledad. "Applied T-RFLP Analyses for the Identification and Characterization of Microbial Populations Associated With Damping-Off Incidence in a Transitional Organic Cropping System." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1218471106.
Full textChen, Bojun. "Nitric Oxide Production: A Mechanism for Inhibition of Chlamydia Trachomatis Replication." Digital Commons @ East Tennessee State University, 1993. https://dc.etsu.edu/etd/2653.
Full textOliveira, Débora Cristina de. "Esterilização por óxido de etileno: estudo da efetividade esterilizante de misturas não explosivas e compatíveis com a camada de ozônio." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-30092011-122525/.
Full textTaking into account the importance of the sterilization process applied to medicines and medical devices, different kinds of methods have been developed, also applicable to heat sensitive materiais. Ethylene oxide is the process most widely applied to medical devices. Due its explosiveness and inflamability, it has been used associated to non active gases, wich inhibit these properties, mainly the chlorofluorocarbons (CFCs). Recent knowledge about ozone-depleting gases and an international consensus on the need of reducing their effects are promoting a search for alternative chemicals. From these, one of the most interesting are the hydrochlorofluorocarbons (HCFCs) which, besides having this role, can also be used as transitional compounds while more environmentally suitable compounds are not available. This paper aims to compare two ethylene oxide sterilization mixtures: Oxyfume 12R (using CFC 12) and Oxyfume 2002R (using HCFCs 22 and 124), under different concentrations (450mg/L and 600mg/L) and different temperatures (45°C, 55°C and 65°C). To accomplish this procedure, sub-Iethal challenges were performed (3, 6, 9, 12 and 15 minutes of exposition), in a total of 180 cycles, using six biological indicators per cycle prepared in a laboratory, in a total of 1080 units, as well as two others purchased from an American supplier (AttestR 1264, 3M), in a total of 360 units. The former indicators were obtained using Bacillus subtilis var. niger ATCC 9372 in Roux bottles, innoculated on paper carriers and wrapped up on protective packaging. The posterior lethality study and D value calculation highlighted the highest resistance of AttestR indicators in comparison with the laboratory ones. This can be explained by different leveIs of spores purification, alongside with the differences between the carriers and packaging used in both cases. The sterilizing efficacy of Oxyfume 12R and Oxyfume 2002R revealed equivalent results, even in different concentrations. The influence of higher temperatures was efficient (p=1,0). Aiming at occupational safety, environmental monitoration was also performed related to ethylene oxide, using DragüerR detection tubes and foley pump. The results, obtained in different positions and moments under 1 ppm, confirmed that the engineering concepts indicated by the Portaria Interministerial nº 482 from 16 april 1999, published on the 19th of the same month in the Diário Oficial, offer residual safe levels compatible with human presence. It is therefore gratifying to conclude that the sterilization process using Oxyfume 2002R is both an efficient contribution to a safe utilization of products and, at the same time, to preserve the animallife on Earth.
Hackmann, Timothy John. "Responses of Rumen Microbes to Excess Carbohydrate." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1364922613.
Full textJesus, Camila Knysak Camargo de. "Reaproveitamento de meio de cultivo de Arthrospira platensis tratado por processos de microfiltração e ultrafiltração." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/9/9134/tde-20052016-172745/.
Full textPhotosynthetic microorganisms, including here the genus Arthrospira, have been produced worldwide in large scale, in a market which generates more than $ 1 billion a year. The industrial production uses huge volume of water with high salinity to produce thousands of tons of microalgal biomass. It is increasing the use of membrane separation process in water treatment, proving to be a technique that generates high quality water, compact and easy both installation and automation. In this study, it was evaluated this technology for the recycling of the culture medium to produce photosynthetic microorganisms, aiming to contribute to the sustainability of this production process. The effluent from Arthrospira platensis culture originating from batch process in laboratory-scale open raceway tanks was treated by tangential flow filtration with microfiltration (MF) (membrane pore size of 0.65 µm and 0.22 µm) and ultrafiltration (UF) (molecular weight cut-off of 5,000 Da), using transmembrane pressure (TMP) from 22.5 up to 90 kPa. MF processes led to average reductions of 53,9±1.3% and 93.1±1.1% of natural organic matter (NOM) and pigments in the exhausted media, respectively. With the use of UF process, whose media were pre-treated by MF (0.22 µm and 22.5 kPa), the average NOM and pigments reductions were 57.2±0.5% and 94.0±0.8%, respectively. The MF process with TMP of 22.5 kPa led to maximum cell concentrations (Xm) equivalent to those obtained with the new medium. The use of membrane of 0.65 µm under TMP of 22.5 kPa led to an average loss of 2.9%, 22.7% and 16.4% of the nutrients carbonate, phosphate and nitrate, respectively, but correcting the concentration of these nutrients to those values present in the standard medium led to obtain the highest Xm (3586.6±80 mg L-1), cell productivity (505.0±11.6 mg L-1 d-1) and nitrogen-to-cell conversion yield (29.6±0.7 cells mg mg-1). The protein content of this biomass was statistically equal to that one obtained from cultivation with standard new medium. Data from this study show that membrane filtration processes are promising for reuse media in cultivation of photosynthetic microorganisms.
Soriani, Renata Rabêlo. "Irradiação de drogas vegetais: aspectos microbiológicos e químicos." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-14062016-190423/.
Full textDespite industrialization in the pharmaceutical area, the use of vegetable drugs is being considered a therapeutical alternative either for underprivileged people or for those who are already used to their consumption. Furthermore there is presently a tendency to value those species with healing property, mainly the Brazilian ones, what is stimulating research and their increasing consumption. Thus, issues concerning the quality of such drugs are extremely important, mainly due to the fact that their microbial load offers potential risks to consumers. Consequently, the evaluation of their sanitary conditions has become fundamental, also owing to the fact that their therapeutical efficacy can be harmed by the decomposition of their components, as a result of the action of microorganisms. Therefore, physical or chemical decontamination has been employed as a measure to reduce the bioburden. Although these procedures are being legally performed they require studies concerning the stability of the active principles after the process. Gamma irradiation has been one of the most important decontaminating agents, widely used due to its applicability in the absence of water or high temperature and to its property of presenting high penetration and efficiently reducing the viable microbial load. This work aimed at evaluating the effects of different radiation doses over the microbial burden of four kinds of vegetable drugs: artichoke (Cynara scolymus L.), chamomile (Matricaria recutita L.), ginkgo (Ginkgo biloba L.) and guarana (Paullinia cupana H.B.K.). The detection of possible alterations provoked by radiation on the contents of their active principies has also been a goal of this study. The microbiological and chemical analyses were performed before and after irradiation with average doses of 5,5 kGy, 11,4 kGy and 17,8 kGy. The results revealed high contamination levels: average of 4,1 x106 for total aerobic microorganisms and 3,3x105 for fungi. After decontamination the average dose of 11,4 kGy reduced the total aerobic microbial count to levels below or equal to 102 in all drugs, except the chamomile provided by supplier B (3,2x104). For fungi, the lowest dose applied (5,5 kGy) was enough to reduce the count to a level of 10. As to the determination of markers in vegetable drugs, the results obtained presented no significant alterations in cafein contents of guarana or in flavonol glycosides of ginkgo. The samples of chamomile, both prior to and after radiation presented the same yield of essential oil as well as absence of significant differences in the contents of α-bisabolol. On the other hand, a reduction in the concentration of apigenin-7-glycoside after irradiation was observed, what indicates degradation caused by the process. The influence of radiation over artichoke remains unknown due to the absence of adequate methods of extraction and determination of cinarin.
Waldbauer, Jacob Richard. "Molecular Biogeochemistry of modern and ancient marine microbes." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/57991.
Full textCataloged from PDF version of thesis.
Includes bibliographical references.
Biological activity has shaped the surface of the earth in numerous ways, but life's most pervasive and persistent global impact has been the secular oxidation of the surface environment. Through primary production - the biochemical reduction of carbon dioxide to synthesize biomass - large amounts of oxidants such as molecular oxygen, sulfate and ferric iron have accumulated in the ocean, atmosphere and crust, fundamentally altering the chemical environment of the earth's surface. This thesis addresses aspects of the role of marine microorganisms in driving this process. In the first section of the thesis, biomarkers (hydrocarbon molecular fossils) are used to investigate the early history of microbial diversity and biogeochemistry. Molecular fossils from the Transvaal Supergroup, South Africa, document the presence in the oceans of a diverse microbiota, including eukaryotes, as well as oxygenic photosynthesis and aerobic biochemistry, by ca. 2.7Ga. Experimental study of the oxygen requirements of steroid biosynthesis suggests that sterane biomarkers in late Archean rocks are consistent with the persistence of microaerobic surface ocean environments long before the initial oxygenation of the atmosphere. In the second part, using Prochlorococcus (a marine cyanobacterium that is the most abundant primary producer on earth today) as a model system, we explored how microbes use the limited nutrient resources available in the marine environment to make the protein catalysts that enable primary production. Quantification of the Prochlorococcus proteome over the diel cell-division cycle reveals that protein abundances are distinct from transcript-level dynamics, and that small temporal shifts in enzyme levels can redirect metabolic fluxes. This thesis illustrates how molecular techniques can contribute to a systems-level understanding of biogeochemical processes, which will aid in reconstructing the past of, and predicting future change in, earth surface environment
by Jacob Richard Waldbauer.
Ph.D.
Atobe, Jane Harumi. "Efeito do leite fermentado contendo Lactobacillus casei Shirota na microbiota intestinal de crianças sob terapia antimicrobiana." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/9/9136/tde-30012009-091742/.
Full textAntimicrobial treatment can destroy the balance of gastrointestinal microflora, which may induce clinical symptoms, mainly diarrhoea. The influence of Lactobacillus casei Shirota on the intestinal microflora was assessed in a prospective, randomised, double-blind controlled study. Sixty-three hospitalised children, with ages between 2 and 14 years, under treatment with β-lactam antibiotics were randomised to receive milk fermented by L. casei Shirota, 108-9 CFU/mL, or placebo during the antimicrobial treatment. Stool samples were collected before the administration of fermented milk, during the antibiotic treatment, and one week after the end of treatment with the antimicrobial agent and the ingestion of fermented milk. The number of L. casei Shirota increased significantly (p<0.05) during the period in which fermented milk was ingested. An increase in the Pseudomonas aeruginosa (p<0.05) and Clostridium sp (p<0.05) count was observed in the microflora of the group that received placebo, mainly in the last period of antimicrobial therapy. The alteration of intestinal microflora as a result of antibiotic treatment was found by the reduction of acetate (p<0.05), butyrate (p<0.05) and formate (p<0.05). The variation in bacterial count proved not to be significant for the children under antimicrobial treatment who received fermented milk, while the placebo group showed imbalance of microflora with the result of the altered bacterial count. About 50% of the children still presented L. casei Shirota in their stools after interrupting the ingestion of fermented milk for one week. This study showed that ingestion of fermented milk containing L. casei Shirota promoted a much faster re-balance of the intestinal microflora when compared to the group that ingested a placebo.
Lenhardt, Elizandra Hertel. "Avaliação da produção e viabilidade de esporos de Bacillus atrophaeus ATCC 9372 utilizando resíduos do processamento de suco de laranja." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-12082016-091342/.
Full textBrazil is one of the world´s largest producers of oranges juice, in the same way that the production is high the amount of generated waste is also significant. It is well known that these residues, which include seeds, peel and pulp, are rich in nutrients that could be used as substrate by microorganisms whether for growth or for obtaining by-products. Bacillus atrophaeus ATCC 9372 spores are used as biological indicators, BIs, in thermal processes due to their ability to form heat-resistant spores. This study aimed to evaluate the use of orange juice processing waste as an alternative culture media to obtain B. atrophaeus spores, to be applied in industrial processes. To orange\'s bagasse (from 1.0 g to 20.0 g), obtained by processing in a fruit\'s centrifuge, 100 mL of water was added, and sterilized at 121 ºC. An aliquot of 0.1g/L of Bacillus atrophaeus spores was inoculated to bagasses\'s media and incubated at 150 rpm / 37 ºC up to 6 days. As cells (µmáx = 0.0238 h-1 and Px = 0.0787 g/L.h, for 5.0 g of bagasse) were obtained, a factorial experimental design 22, with star-shaped model and 6 central points, was performed considering the bagasse concentration and the media volume used. Values of pH, biomass, viable spores and their thermal resistance at 102 ºC were determined. It was observed that pH increased after cultivation and major values of spore concentration achieved were 1.73 x 109 spores /mL and 5.75 x 109 spores /mL after 3 and 6 days, respectively. Decimal reduction times determined ranged from D102C = 0.92 min to D102C = 2.71 min and from D102C = 1.34 min to D102C = 3.98 min after 3 and 6 days of incubation, correspondingly. The regression analysis showed that the development of spores in bagasse can be defined by the equation: Spores = , p=0.000, R2 =0.452 and time has a positive influence in the spore formation. Results demonstrated media prepared with oranges\' bagasse were capable to grow and to develop B. atrophaeus heat-resistant spores, being an alternative to add value to a waste that would be discarded, generating a product of great importance in the pharmaceutical field.
Braff, Jennifer C. "Construction and phenotypic screening of mid-size insert marine microbial environmental genomic libraries." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/43722.
Full textIncludes bibliographical references (leaves 52-56).
Functional screening of environmental genomic libraries permits the identification of clones expressing activities of interest without requiring prior knowledge of the genes responsible. In this study, protocols were optimized for the construction of mid-size DNA insert, inducible expression environmental genomic plasmid libraries for this purpose. A library with a mean insert size of 5.2 kilobases was constructed with environmental DNA isolated from surface ocean water collected at Hawaii Ocean Time-series station ALOHA in plasmid cloning vector pMCL200 under the inducible control of the PLAC promoter. To begin to evaluate the utility of such libraries for gene expression-based screens, this library was screened phenotypically for clones expressing genes that confer fluorescence or distinctive coloration on colonies of host Escherichia coli cells, and results were compared to those for a fosmid library constructed from the same marine microbial DNA sample. Ecologically relevant sequences were identified in both libraries, and each was observed to offer both advantages and disadvantages. Results of this study suggest that mid-size insert plasmid libraries under the control of inducible promoters can provide a useful and complementary approach for both functional screening and shotgun sequencing of environmental genomic libraries.
by Jennifer C. Braff.
S.M.
Mattos, Angela Franco. "Qualidade microbiana: influência de corantes e pigmento no método de bioluminescência." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-08012018-112246/.
Full textThe analysis of the microbiology quality of raw materiais and finished products by means of the conventional technique of counting of microorganism demands high time of work and supplies resulted in period of not compatible time with the development of the technology. The rapid methods provide reliable and cost effective analysis for the microbiological evaluation the pharmaceutical and cosmetic industry. The ATP Bioluminescence detect the presence or absence of microorganisms the reduction in detection times and analysis from 72 hours to 24 hours. The bioluminescence assay is based upon the light-producing enzyme luciferase that will hydrolyze ATP to produce light. Light production is detected by a luminometer and recorded as relative light units (RLU). The purpose of this investigation was to develop and validate the use an ATP bioluminescence assay for detection microbial contamination in artificially contaminated commercial Green Nº 7 pigment and FD&C Blue Covanor e o FD&C Red Nº 5 dyes with some microbial cultures, TAT (Tryptone-Azolectin-Tween) , DE (Dey Engly Neutralization Broth) e LB (Letheen Broth), and to compare the results against standard microbiological analysis. The first step in validation of the ATP bioluminescence system was to determine the sample effect of the sample suspensions on the bioluminescence reaction where analyzed to determine whether the sample contained nonmicrobial ATP. The sensitivity of the assay to detect different levels of Escherichia coli ATCC 8739, Burkholderia cepacea ATCC 25416, Staphylococcus aureus ATCC 6538, Candida albicans ATCC 10231 was analyzed by spiking into the samples suspensions. For C. albicans contamination detection has not been possible because it has required more time than bacteria. The microbial culture TAT without addition of polissorbato 80 has presented the best conditions for the validation of the Green pigment n° 7. For dyes has still been necessity of studying other microbial culture, reagents and conditions that they propitiate resulted adequate in compliance with the specifications for the validation.
Barbieri, Daniela <1985>. "Human papillomavirus (HPV) and associated diseases: between applied diagnostic and basic research." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5314/.
Full textIl Papillomavirus umano (HPV) è causa dei carcinomi della cervice uterina (tra cui adenocarcinomi, AdCa) ed è associato ad un sottogruppo di tumori dell’orofaringe (OPSCCs). Nonostante il rischio di sviluppo di tumore sia associato all’infezione da parte di alcuni genotipi virali, principalmente HPV16 e 18, il DNA virale da solo sembra non essere sufficiente in campo diagnosico. Inoltre, per tumori orofaringei il ruolo del virus non è ancora del tutto chiaro. Nella prima parte della tesi, sono state confrontate le performance riguardo la genotipizzazione di HPV su campioni clinici cervicali di una tecnica innovativa, basata su amplificazione e pirosequenziamento, e una di routine, basata su amplificazione e ibridazione inversa. Lo studio ha evidenziato performance simili tra le due metodiche, sottolineando per il sequenziamento una maggiore specificità e capacità di rilevare varianti intratipo. Nella seconda parte sono stati analizzati marker virologici (genotipizzazione, espressione delle oncoproteine virali, carica virale, stato fisico e metilazione del genoma di HPV16) in funzione dei dati clinici disponibili, per un possibile impiego nella diagnosi/prognosi di AdCa cervicali e OPSCCs HPV-associati. HPV16 si è confermato il genotipo prevalente in entrambe le popolazioni. La frequenza di metilazione nel promotore precoce virale ha mostrato una tendenza ad essere associata ad invasione negli AdCa, e ad una prognosi peggiore negli OPSCCs, emergendo come il più promettente marker diagnostico/prognostico. La terza parte, svolta presso il DKFZ di Heidelberg (Germania), ha visto l’analisi della risposta alla transfezione di IFN-k in linee cellulari tumorali HPV16-positive della cervice uterina e della regione testa-collo, per valutarne l’impiego terapeutico. Dopo 24h, è stato osservato un incremento dell’espressione di IFN-b e, di conseguenza, una up-regolazione dei geni coinvolti nella presentazione antigenica (MHC classe I ed immunoproteasoma) e nella risposta antivirale, specialmente nelle cellule cervicali, suggerendo la presenza di diversi meccanismi patogenetici tra tumori HPV-positivi dei due distretti anatomici.
Ishii, Marina. "Determinação dos parâmetros cinéticos de resistência térmica da Proteína Verde Fluorescente recombinante (GFPuv)." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-25062012-114829/.
Full textTransformed cells of Escheríchía coli DH5-α expressing recombinant green fluorescent protein (GFPuv, excitation and emission peaks at 394nm and 509nm), were subjected to the three-phase partitioning (TPP) method and the release extracts were eluted through methyl HIC column with a buffer solution (10 mM Tris-HCI, 10mM EDTA, pH=8.0). The purpose of this work was to study the thermal stability of the TPP-extracted recombinant protein, GFPuv, to determine its utility as a quick, accurate and economical biological indicator for moist heat-treatments. The thermal stability of the extracted GFPuv was studied in different buffer solutions (acetate, phosphate and tris-HCI 10mM) in the range of pH between 5.0 and 9.0 and at temperature between 75-95°C. The thermal resistance parameters determinated were: decimal reduction times (D-values, min), z-value (۰C), Q
Aguilar, Mónica Alejandra Pavez. "Caracterização molecular da resistência aos carbapenêmicos em enterobactérias isoladas em hospitais brasileiros." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/9/9136/tde-28092009-144325/.
Full textIntroduction: After emergence, and dissemination of extended spectrum β-lactamases (ESBL) in members of the Enterobacteriaceae family, carbapenem antibiotics (imipenem, meropenem, ertapenem) have been the therapy of choice, since they are stable to ESBL hydrolysis. Unfortunately, in 2005, the first fatal case of infection by carbapenem-resistant Klebsiella pneumoniae was related in our country. From this episode, new infection cases, including by other genders of Enterobacteriaceae such as Enterobacter, Providencia and Escherichia, began to appear. Regarding carbapenem resistance mechanisms, expression of carbapenem hydrolyzing enzymes has been worldwide reported, whereas interplay between impermeability and AmpC or ESBL production has been sporadic. Furthermore, integrons and plasmids have been associated with mobilization of genetic determinants. The aim of this study was to characterize the mechanisms of resistance to carbapenems, their genetic mobilization and clonal dissemination in enterobacterial isolates recovered from clinical samples in Brazilian hospitals. Material and methods: 28 imipenem-resistant isolates recovered from 8 hospital centres were studied. Phenotypic profiles were characterized by: i) MIC of carbapenems in the presence/absence of β-lactamase inhibitors; ii) bioassay for β-lactamase production; iii) SDS-PAGE to investigate absence of outer membrane porins (OMPs). Molecular characterization of β-lactamase-mediated resistance was made by PCR and DNA sequencing and their plasmid localization was evaluated by transformation. Finally, epidemiological typing was performed by ERIC-PCR, being confirmed by PFGE. Results: 25 isolates were confirmed as being resistant to imipenem (MIC 8-128 µg/mL), exhibiting a multidrug-resistant profile, including to cefoxitin (MIC90 ≥32 µg/mL). Two main mechanism of resistance were identified: i) hydrolysis of carbapenem by class B (IMP-1-like MBL) and class A (KPC-2) enzymes, (the latter being recently reported in our country), and ii) outer membrane impermeability associated to AmpC enzyme production (plasmid-mediated CMY-2 for E. coli and chromosomal AmpC for E. aerogenes), which was the most prevalent mechanism found. Eighteen of 28 isolates lacked 36kDa OMP, which is responsible for uptake of carbapenem antibiotics. The blaKPC-2 and blaCMY-2 genes were successful transferred to E. coli DH10B, confirming the plasmid location of both genes. Co-production of carbapenemases or AmpC and CTXM enzymes was confirmed in 68% of isolates, and molecular typing showed clonal dissemination of IMP-1-, plasmid AmpC- and chromosomal AmpC-producing isolates. Otherwise, KPC-2-producing isolates were not clonally related. Conclusion: The characterization of resistance mechanisms to carbapenems, in this study, reveals a change in the resistance patterns among Enterobacteriaceae family members in Brazilian hospitals, due to versatility of isolates to acquire new resistance determinants, which it has favoured the adaptation to hostile environments. Lack of 36 kDa OMP was the most frequent resistance mechanism, being associated to co-production of β-lactamases. Finally, molecular typing denote a clonal dissemination of imipenem-resistant isolates in Sao Paulo city, with exception of KPC-2-producing isolates, which have been described in other Brazilian cities, suggesting a horizontal gene transfer.
Caleb, Oluwafemi James. "Microbial community structure as an indicator of soil health in apple orchards." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4133.
Full textENGLISH ABSTRACT: The relationship between various land management practices, soil properties and the soil microbial communities are complex and little is known about the effect of these interactions on plant productivity in agricultural systems. Although it would be advantageous to have a single organism or property that can be used as a measure of soil health, it may not be possible. Soil organisms which include both the microorganisms as well as soil fauna are subjected to the effect of their immediate environment. This microenvironment in turn is determined by the soil properties as well as above ground flora and their interactions. Most soil indicators interact with each other, and these interactions can modify or influence the soil properties. The complexities of the interactions between critical soil indicator values often preclude its practical use by land managers and policy makers. However, soil microbial communities (e.g. diversity and structural stability) may serve as a relative indicator of soil quality. These communities are sensitive to land management practices and changes in the microenvironment. The objective of this study was to gain an understanding of the complex relationships by investigating the effect of conventional, integrated and organic apple production systems on the physical, chemical and biological (particularly soil microbial diversity) properties of the soil. Automated Ribosomal Intergenic spacer analysis (ARISA) was used to characterise fungal (F-ARISA) and bacterial (B-ARISA) communities from soil samples obtained from an experimental apple orchard in Elgin, Grabouw. The intergenic spacer (ITS) region from the fungal rRNA operon was amplified using ITS4 and fluorescently FAM (6- carboxylfluorescein) labelled ITS5 primers. Similarly, the 16S-23S intergenic spacer region from the bacterial rRNA operon was amplified using ITSR and FAM-labelled ITSF primers. The sensitivity of the technique allowed us to discriminate between the soil microbial communities of the different treatments. From our results we observed significant increase (p < 0.05) in the fungal community diversity between the February and April samples, while the bacterial community diversity was consistent (p > 0.05). Also, treatments with mulch showed a significantly higher microbial diversity than the other treatments at a 5 % significance level. Fungal communities showed significant correlation with the potassium concentration in the soil, while bacterial communities depicted a significant correlation with the soil phosphorous concentration. Based on the results we concluded that different management practices have a significant effect on the soil microbial communities and that these communities are particularly sensitive to small changes in the environment. However, there is still a need to determine what the composition of the soil microbial communities are to be able to correlate our observations with soil health.
AFRIKAANSE OPSOMMING: Die verhouding tussen verskillende landboubestuurspraktyke, grondeienskappe en die mikrobiese gemeenskappe in grond is kompleks en weinig is bekend oor die uitwerking van hierdie interaksies op die produktiwiteit van landboustelsels. Alhoewel dit voordelig sou wees om ‘n enkele organisme of eienskap te kan hê wat die gesondheid van grond kan meet, sal dit dalk nie moontlik wees nie. Grondorganismes wat die mikroörganismes sowel as die grondfauna insluit, is onderworpe aan die invloed van hulle onmiddelike omgewings. Hierdie mikro-omgewings op hulle beurt word weer beïnvloed deur die grondeienskappe sowel as die die oppervlak flora en hulle wisselwerkinge. Meeste van die grondaanwysers toon ook wisselwerkinge met mekaar, en hierdie wisselwerkinge kan die grondeienskappe beïnvloed or selfs verander. Die kompleksiteit van die wisselwerkinge tussen kritiese grond aanwysers is meestal die rede waarom dit nie deur grondbestuurders en beleidsmakers gebruik word nie. Dit is ongeag die feit dat grond mikrobiese gemeenskappe (bv. diversiteit en stukturele stabiliteit) mag dien as ‘n relatiewe aanwyser van grondkwaliteit. Hierdie gemeenskappe is sensitief vir bestuurspraktyke en veranderinge in die mikro-omgewing. Die doel van die studie was om die ingewikkelde verhoudings in die grondgemeenskappe te bestudeer en die uitwerking van konventionele, geïntegreerde en organiese appel produksie sisteme op die fisiese, chemiese en biologiese eienskappe (veral die grond mikrobiologiese diversiteit) te bepaal. Geoutomatiseerde Ribosomale Intergeniese Spasie Analise (ARISA) is gebruik om die fungus (F-ARISA) en bakteriese (B-ARISA) gemeenskappe van grondmonsters wat vanaf ‘n proef appelboord in Elgin (Grabouw) verkry is, te bepaal. Die intergeenspasie (ITS) area van die fungus rDNA operon is vermeerder deur die ITS4 en fluoresserende FAM (6-karboxylfluorescein) gemerkte ITS5 inleiers te gebruik. Soortgelyk is die 16S-23S intergeenspasie area van die bakteriese rDNA operon vermeerder deur ITSR en FAM-gemerkte ITSF inleiers te gebruik. Die sensitiwiteit van die tegniek laat ons toe om te onderskei tussen die grond mikrobiese gemeenskappe vanaf verskillende grondbehandelings. Vanuit die resultate kon ons aflei dat daar ‘n toename (p < 0.05) in die fungus gemeenskap diversiteit vanaf Februarie to April was terwyl die bakteriese gemeenskap ‘n konstante diversteit getoon het (p > 0.05). Behandelings met grondbedekking het ook ‘n beduidend hoër mikrobiese diversiteit getoon as ander behandelings. Fungus gemeenskappe het beduidende korrelasies getoon met kalium konsentrasies in die grond, terwyl bakteriese gemeenskappe ‘n beduidende korrelasie getoon het met grond fosfor konsentrasies. Gebaseer op die resultate kon ons aflei dat verskillende bestuurspraktyke ‘n uitwerking kan hê op die grond mikrobiese gemeenskappe en dat hierdie gemeenskappe sensitief is vir klein veranderinge in die omgewing. Dit sal egter nog nodig wees om die spesifieke samestelling van die grond mikrobiese gemeenskappe te bepaal voor ons hierdie waarnemings kan korreleer met grondgesondheid.
Elkner, Timothy Edward. "Photosynthate production and partitioning in apple leaves." Diss., Virginia Tech, 1990. http://hdl.handle.net/10919/27647.
Full textPh. D.
Boyd, William Alastair. "The effect of high hydrostatic pressure on the microbial quality of apple juice." Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326356.
Full textIshii, Marina. "Aplicação da proteína verde fluorescente (GFPuv) como indicador biológico na validação da autoclavação de soluções parenterais e da esterilização por óxido de etileno de itens termolábeis. Comparação com esporos de Bacillus subtilis." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-23082017-115802/.
Full textThe recombinant Green Fluorescent Protein, GFPuv is an attractive system marker due to its ability to emit fluorescence when exposed to ultraviolet light, without use of substrates or complex environment. Being a stable molecule even in the presence of organic substances, temperatures above 70°C and wide range of pH, it is a potential Biological Indicator, BI, for many applications, including thermal processes. GFPuv thermal stability was evaluated by the loss of fluorescence intensity expressed in decimal reduction time (D-value, min), the exposure time required to reduce 90% of the GFPuv initial fluorescence intensity. GFPuv (3.5-9.0 µg/mL), expressed by E. coli and isolated by Three Phases Partitioning, TPP extraction with Hidrophobic Interaction Chromatography, HIC, was diluted in buffered solutions (each 10 mM: Tris-EDTA, pH 8; phosphate, pH 6 and 7, and acetate, pH 5) and in water for injection, WFI; pH = 6.70 (± 0.40), and exposed to temperatures of 25°C and between 80°C and 95°C. At 95°C, the D-value for GFPuv in 1.5%-50% glucose, ranged from: (i) 1.63 ± 0.23 min in acetate pH 5; (ii) 2.64 ± 0.26 min in WFI; (iii) 2.50 ± 0.18 min in phosphate, pH 6; (iv) 3.24 ± 0.28 min in phosphate, pH 7, (v) 2.89 ± 0.44 min in Tris-EDTA, pH 8. Sodium cloride provided a positive influence over GFPuv stability. In Tris-EDTA solutions, the addition of 15% and 20% of NaCl doubled the thermal stability of GFPuv (D = 65.79 min and D = 18.12 min at 80°C, and 85°C, respectively, in relation to the solutions without NaCl. For ethylene oxide sterilization processes (45°C-60°C), GFPuv can be used as biological indicator to monitor gas distribution into the chamber. After processing, the protein concentration varied by 80%, showing distinct areas into the chamber. In autoclave, GFPuv in solution showed thermal resistance in phosphate pH 7.0 solution (F-value = 2.53 (± 0.12) min. When expressed by Bacillus subtilis spores, the fluorescence intensity was kept constant after thermal processing. The thermal stability of GFPuv provides the basis for its potential utility as a fluorescent biological indicator to assess the efficacy of the treatment of liquids and materials exposed to steam.
Bernier, Julie. "A study of fungal leaf decomposition in relation to biological control of the apple scab pathogen, Venturia inaequalis." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23383.
Full textLuera, Pena Wilmer Edgard. "Uso de modelos preditivos no crescimento e inativação de esporos de Alicyclobacillus acidoterrestris em suco de laranja e maça." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255407.
Full textTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Doutorado
Ciência de Alimentos
Doutor em Ciência de Alimentos
Marynowska, Martyna. "Unravelling the termite digestion process complexity - a multi-omics approach applied to termites with different feeding regimes." Doctoral thesis, Universite Libre de Bruxelles, 2020. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/304812.
Full textDoctorat en Sciences
info:eu-repo/semantics/nonPublished
Yamada, Kathryn K. "INACTIVATION OF FOODBORNE PATHOGENS DURING CIDER FERMENTATION, IN A CIDER MODEL SYSTEM AND COMMERICAL CIDER." DigitalCommons@CalPoly, 2020. https://digitalcommons.calpoly.edu/theses/2134.
Full textGarrett, Andrew Robert. "Antioxidants in Cancer Research and Prevention: Assay Comparison, Structure-Function Analysis, and Food Product Analysis." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2735.
Full textFernandes, Dielle Aurelia. "Use of Gamma Irradiation as an Intervention Treatment to Inactivate Escherichia coli O157:H7 in Freshly Extracted Apple Juice." Chapman University Digital Commons, 2019. https://digitalcommons.chapman.edu/food_science_theses/6.
Full textFontes, Luciana Cristina Brigatto. "Uso de solução conservadora e de películas comestíveis em maçãs da Cultivar Royal Gala minimamente processadas: efeito na fisiologia e na conservação." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/11/11141/tde-09092005-144121/.
Full textOne of the current proposals to increase the shelf life of the minimally processed (MP) fruits is the investigation of a material that is adherent to the cut surface of the fruit in order to minimize physiological, physico-chemical and microbial deteriorations. The goal of the study is to evaluate the effect of preservative solution and edible coatings in the conservation of the MP apples of Royal Gala cultivar during the refrigerated storage. The treatments are control, the preservative solution (1% of ascorbic acid; 0.5% of citric acid; 0.7% of NaCl; 0.25% of CaCl2) and the filmogenic solution associated with the preservative one. It was tested the dextrin (5.5%), cassava starch (3%) and sodium alginate (2%) with CaCl2 (0.6%). The quality of the MP apples was monitored by physiological, physical, physico-chemical, microbiological and sensorial analysis until the 13th day of storage. The preservative solution decreased the respiratory rate and the ethylene production compared to the control and, promoted a lighter pulp. The firmness of these apples increased with the time of storage. The treatment with coatings showed an average decrease of 38% in the respiratory rate and more than 50% in ethylene production compared to the control, being the alginate based the most efficient. The alginate coating, seen from a scanning electron microscope, detaches from the others (dextrin and cassava starch) because of its homogeneities and absence of pores, fact that contributed to its efficiency in controlling the respiratory rate and ethylene production. The MP apples with alginate coating presented a better retention of moisture in the beginning of storage, however, there was significant loss of moisture content with the storage time. The higher soluble solids concentrations were verified in the apples of control, with conservative solution and with alginate. Apples with alginate presented less acidity and a darker coloration among the treatments because of the pH and the coloration of the filmogenic solution itself. In the apples in control, the firmness of the tissue decreased during storage and in the other treatments, the tendency was the opposite. The cover of dextrin and cassava starch tended to likely influence the physical and physico-chemical characteristics of the apples, showing intermediated values compared to preservative solution and alginate treatments. In the whole fruit (before the processing), it was detected absence of Salmonella. As well as in the MP apples treated with or without coatings, it was detected no total and fecal coliforms during storage. In the treatment that used only the preservative solution, the MP apples presented grades very close to natural (apples just cutted) by the quantitative descriptive sensorial analyses, thus having the best acceptation related to the appearance, smell, taste and texture. The treatments with coatings presented a good acceptation from the tasters, except the MP apples with alginate that appear a little strange due the coating bright. The product was classified as artificial in appearance and deteriorated-fruit in taste.
Van, Schoor Louise. "Effect of biological amendments on soil microbial properties and performance of pome fruit trees." Thesis, Stellenbosch : Stellenbosch University, 2009. http://hdl.handle.net/10019.1/4602.
Full textENGLISH ABSTRACT: The global movement in agriculture is towards more environmentally friendly, sustainable production practices, since the role of soil microbial functions in ensuring crop production and soil fertility has become more evident in agricultural systems. Furthermore, with the impeding phase-out of methyl bromide, apple replant disease (ARD) is becoming an increasingly important problem and biological management practises are needed. Since microbial activity is generally carbon-limited in agricultural soil, it is widely accepted that management practices providing a range of organic compounds on a regular basis will tend to maintain an active and diverse microbial population. It was hypothesised that the application of various biological amendments can affect soil microbial numbers and function, thereby having a positive effect on fruit tree growth and yield. The effect of continued applications of organic material, various microbial inoculants and biostimulants on tree performance were evaluated in conventional management systems. Field trials were established in a conventional pear orchard, potential apple replant disease sites, as well as an optimally managed, high density apple orchard under controlled fertigation. The use of compost, compost extracts, a Bacillus inoculant and humates were investigated intensively. Furthermore, to improve our understanding of soil biological systems a combination of simple, practical methods were used to evaluate the effect of biological amendments on soil microbial properties and effects were related to tree performance. Regular application of compost extract in combination with compost showed the most significant effect in improving tree performance in commercial pome fruit orchards under various conditions. In the pear orchard, cumulative yield over the first two seasons was improved by more than 50% compared to controls, while in the fertigated orchard yield was improved by 22%. Biological amendments also showed improved growth in orchards suffering from stunted growth symptoms typical of ARD. However, in severe ARD cases methyl bromide fumigation showed the most consistent effects. Other biological amendments which showed positive effects on yield were application of Bacillus inoculants (Biostart®) in combination with a labile C source and a low dosage humate product, as well as a combination of compost and humates. It was clear that a combination of labile organic matter and a diverse group of microorganisms showed most promise. Although for some specific treatments increased microbial numbers and activity may have resulted in improved tree performance, in general, changes in culture-based plate counts, soil enzyme activity and carbon utilisation profiles could not be used as an indicator of yield. It was suggested that improved synchronisation of nutrient release and plant uptake, as well as microbial phytohormone production, may play an important role in improving tree performance with application of biological amendments. More research is needed on the exact mechanisms through which compost extracts improve yield and studies on root growth proliferation, as well as effects in the rhizosphere are recommended.
AFRIKAANSE OPSOMMING: Binne lanbouverband is daar tans wêreldwyd die neiging om die uitwerking van produksie-praktykte op die omgewing in ag te neem en sodoende meer verantwoordelik op te tree. Omdat die belangrike rol wat grondmikro-organisme funksionering in volhoubare verbouingspraktyke speel nou deeglik besef word, word meer volhoubare bestuurspraktyke bepleit. Hiermee saam, noodsaak aspekte soos die uitfasering van metielbromied vir die beheer van appelhervestigingsiekte, dat biologiese bestuurspraktyke meer aandag geniet. Daar word geredelik aanvaar dat gereelde toediening en aanvulling van organiese materiaal ‘n aktiewe, diverse mikrobe populasie in die grond tot gevolg sal hê. Die hipotese is gestel dat die toediening van ‘n verskeidenheid biologiese produkte grondmikrobe getalle en werking gunstig kan beïnvloed. Dit kan moontlik weer aanleiding gee tot positiewe reaskies wat die groei en drag van vrugtebome betref. In hierdie studie is die uitwerking van voortgesette toedienings van organiese materiaal, mikrobiese inokulante, asook biostimulante, op die prestasievermoë van vrugtebome ondersoek. Veldproewe is uitgelê in ‘n konvensionele peerboord, verskeie boorde met moontlike appelhervestigingsiekte probleme, asook ‘n hoëdigtheidsaanplanting appelboord onder optimale bestuur. ‘n Deeglike ondersoek is gedoen met betrekking tot die gebruik van kompos, komposekstrak, Bacillus-inokulante en humate. Eenvoudige, praktiese metodes is aangewend om vas te stel hoe biologiese toevoegings grondmikrobe eienskappe beïnvloed en of dit verband hou met veranderinge in boomprestasie. Die studie het aangetoon dat die gereelde toediening van komposekstrak saammet kompos, betekenisvolle verbetering in boomprestasie van kernvrugboorde teweeg bring onder verskeie omstandighede. Die kumulatiewe opbrengs van ‘n peerboord is oor twee seisoene met meer as 50% verhoog teenoor die kontrole. In ‘n optimaal bestuurde appelboord onder sproeibemesting, is opbrengs met 22% verhoog in vergelyking met die kontrole. Biologiese toevoegings het ook groei verbeter in boorde waar appelhervestigingsiekte bome se groei vertraag het. In die geval van ernstige appelhervestigingsimptome het metielbromied egter steeds die mees konstante positiewe uitwerking gehad. Ander biologiese toevoegings wat ‘n gunstige uitwerking op opbrengs getoon het, was ‘n kombinasie van Bacillus inokulante, ‘n lae dosis humaat en ‘n aktiewe koolstofbron, asook kompos in kombinasie met humate. Dit is duidelik dat ‘n kombinasie van ‘n maklik afbreekbare koolstofbron (soos kompos) tesame met ‘n diverse groep mikroorganismes mees belowend is vir gebruik in biologiese verbouingssisteme. Resultate toon dat veranderings in aantal organismes gemeet deur plaattellings, die aktiwiteit van grondensieme, en verbruikspotensiaal van verskillende koolstofbronne, nie as ‘n aanduiding van boomprestasie gebruik kan word nie. Daar is voorgestel dat verbeterde sinkronisasie van voedingselementvrystelling en plantopname, sowel as produksie van plantgroeihormone deur mikrobe, moontlik ‘n rol speel by boomreaksies op biologiese toevoegings. Meer navorsing wat verband hou met die meganisme waardeur komposekstrak opbrengs verbeter, is nodig. Verder word studies op fynwortelontwikkeling sowel as aspekte van die wortelrisosfeer aanbeveel.
Lavin, Philip. "Hur påverkar olika lokala jäststammar aromutveckling och smak vid fermentering av äppeljuice?" Thesis, Högskolan Kristianstad, Fakulteten för naturvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-22102.
Full textThere is an increasing interest in locally produced drinks. Consumers demand products with complex taste profiles. Especially when it comes to wine, beer and cider. Several studies have shown that indigenous strains of microorganisms can be used to produce products that’s deemed more complex than the products based on conventional strains. This has led brewers and winemakers to experiment with both the raw material as well as the local microorganisms in order to develop unique products. In this study, three local strains of Saccharomyces cerevisiae have been studied for potential differences regarding aroma development and taste during fermentation of apple juice. The results from the study showed that the different strains generally behaved the same, and that fermentation during three days resulted in greater taste liking compared to seven days.
Rossi, Franca Gabriela. "The use of Lactic Acid Bacteria to control the growth of foodborne pathogens on fresh-cut fruits and sprout vegetables." DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1559.
Full textLichtfouse, Eric. "Fossiles moléculaires d'intérêt microbiologique, pétrolier, agronomique et environnemental." Habilitation à diriger des recherches, Institut National Polytechnique de Lorraine - INPL, 1998. http://tel.archives-ouvertes.fr/tel-00173971.
Full textPark, Hoon. "Applied and basic aspects of sulfite metabolism in Saccharomyces cerevisiae." Thesis, 1999. http://hdl.handle.net/1957/26551.
Full textGraduation date: 2000
"Computational modeling of the collective fluid dynamics of motile microorganisms." Tulane University, 1997.
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"Novel approaches for the production of fuels and chemicals in Escherichia coli." Thesis, 2012. http://hdl.handle.net/1911/70225.
Full textAgustinah, Widya. "Synergistic Approach for Designing and Enhancing Bioactive Ingredients from Apple and Blueberry for the Management of Early Stages of Type 2 Diabetes." 2012. https://scholarworks.umass.edu/theses/820.
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