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Academic literature on the topic 'Photosynthetic mixed cultures (PMC)'
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Journal articles on the topic "Photosynthetic mixed cultures (PMC)"
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Kirpenko, N. I. "Photosynthetic Activity of Algae in Their Mono- and Mixed Cultures." Hydrobiological Journal 45, no. 4 (2009): 61–73. http://dx.doi.org/10.1615/hydrobj.v45.i4.60.
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Battaglia, Manuela, Marco Andreani, Marisa Manna, Sonia Nesci, Paola Tonucci, Barbara Persini, Gioacchino Robustelli della Cuna, et al. "Coexistence of Two Functioning T-Cell Repertoires in Healthy Ex-Thalassemics Bearing a Persistent Mixed Chimerism Years After Bone Marrow Transplantation." Blood 94, no. 10 (November 15, 1999): 3432–38. http://dx.doi.org/10.1182/blood.v94.10.3432.422k17_3432_3438.
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Bone marrow transplantation (BMT) from an HLA-identical donor is an established therapy to cure homozygous β-thalassemia. Approximately 10% of thalassemic patients developed a persistent mixed chimerism (PMC) after BMT characterized by stable coexistence of host and donor cells in all hematopoietic compartments. Interestingly, in the erythrocytic lineage, close to normal levels of hemoglobin can be observed in the absence of complete donor engraftment. In the lymphocytic lineage, the striking feature is the coexistence of immune cells. This implies a state of tolerance or anergy, raising the issue of immunocompetence of the host. To understand the state of the T cells in PMC, repertoire analysis and functional studies were performed on cells from 3 ex-thalassemics. Repertoire analysis showed a profound skewing. This was due to an expansion of some T cells and not to a collapse of the repertoire, because phytohemagglutinin stimulation showed the presence of a complex repertoire. The immunocompetence of the chimeric immune systems was further established by showing responses to alloantigens and recall antigens in vitro. Both host and donor lymphocytes were observed in the cultures. These data suggest that the expanded T cells play a role in specific tolerance while allowing a normal immune status in these patients.
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Kaewsuk, Jutamas, Worachat Thorasampan, Monthon Thanuttamavong, and Gyu Tae Seo. "Kinetic development and evaluation of membrane sequencing batch reactor (MSBR) with mixed cultures photosynthetic bacteria for dairy wastewater treatment." Journal of Environmental Management 91, no. 5 (May 2010): 1161–68. http://dx.doi.org/10.1016/j.jenvman.2010.01.012.
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Bolinesi, Francesco, Maria Saggiomo, Serena Aceto, Angelina Cordone, Emanuela Serino, Maria Carmen Valoroso, and Olga Mangoni. "On the Relationship between a Novel Prorocentrum sp. and Colonial Phaeocystis antarctica under Iron and Vitamin B12 Limitation: Ecological Implications for Antarctic Waters." Applied Sciences 10, no. 19 (October 5, 2020): 6965. http://dx.doi.org/10.3390/app10196965.
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We collected live mixed natural samples from the northeastern Ross Sea during the austral summer of 2017 and isolated a novel Prorocentrum sp. (Dinophyceae) associated with mucilaginous Phaeocystis antarctica (Coccolithophyceae) colonies. The haptophyte P. antarctica is a key species of the phytoplankton community in the Ross Sea, where blooms are subjected to iron limitation and/or co-limitation with other micronutrients (e.g., vitamin B12) during the summer. We first performed preliminary genetic analyses to determine the specific identity of the novel Prorocentrum sp., which indicated that it represented a previously undescribed species. The formal description of this new species is in process. To further assess its relationship with P. antarctica, we obtained their monospecific and mixed cultures and evaluated their responses to different irradiance levels and iron and vitamin B12 limitation. Our results indicated differential susceptibility of the two species to iron limitation and differential photosynthetic plasticity under high irradiance. Iron limitation reduced colony formation in P. antarctica and decreased the chlorophyll-a content in Prorocentrum sp., whereas B12 limitation did not affect growth or photosynthetic efficiency in either species. In addition, P. antarctica could photosynthesize efficiently under different irradiance levels, due to its ability to modulate the light adsorption cross-section of PSII, whereas Prorocentrum sp. exhibited lower photosynthetic plasticity and an inability to modulate both the maximum photochemical efficiency and effective adsorption cross-section of PSII under high irradiance. The trophic interaction between Prorocentrum sp. and P. antarctica could present ecological implications for the food webs and biogeochemical cycles of the Antarctic ecosystem. Considering the predicted climate-driven shifts in global ocean surface light regimes and changes in iron or vitamin B12 transfer, which are most likely to impact changes in the phytoplankton community structure, our results present implications for carbon export to deeper waters, ecological functioning, and associated biogeochemical changes in the future.
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Hastuti, Sri, Tri Martini, Candra Purnawan, Abu Masykur, and Atmanto Heru Wibowo. "Pembuatan Kompos Sampah Dapur dan Taman dengan Bantuan Aktivator EM4." Proceeding of Chemistry Conferences 6 (September 15, 2021): 18. http://dx.doi.org/10.20961/pcc.6.0.55084.18-21.
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<p>Pembuatan kompos dari sampah dapur dan taman dengan bantuan <em>effective microorganism</em> (EM4) dan <em>microorganism local</em> (MOL) telah dilakukan. Tujuan dari kegiatan ini adalah memanfaatkan sampah yang ada di sekitar untuk dijadikan barang yang lebih berguna. EM4 merupakan kultur campuran dari mikroorganisme yang menguntungkan yang mengandung mikroorganisme fermentasi dan sintetik yang terdiri dari bakteri Asam Laktat (<em>Lactobacillus Sp</em>), bakteri Fotosentetik (<em>Rhodopseudomonas Sp</em>), <em>Actinomycetes Sp</em>, <em>Streptomyces Sp</em> dan Yeast (ragi) dan Jamur pengurai selulose. Bahan ini membantu fermentasi bahan organik tanah menjadi senyawa organik yang mudah diserap oleh akar tanaman. Proses pembuatan kompos dilakukan dengan mencampurkan sampah dapur dan taman dengan penambahan EM4. Proses fermentasi dilakukan variasi waktu 10, 14, 21, 26 dan 32 hari. Hasil pengamatan menunjukkan bahwa semakin lama fermentasi kompos yang dihasilkan semakin baik dimana daun telah hancur berubah bentuk seperti tanah.</p><p><strong><em>Kitchen and Garden Waste Composting using EM4 Activator. </em></strong><em>Composting of kitchen and garden waste with the help of effective microorganisms (EM4) and microorganism local (MOL) has been carried out. The purpose of this activity is to use the waste to become more useful items. EM4 is a mixed culture of beneficial microorganisms. This material contains microorganisms consisting of lactic acid bacteria (Lactobacillus Sp), photosynthetic bacteria (Rhodopseudomonas Sp), Actinomycetes Sp, Streptomyces Sp, and yeast, and cellulose-decomposing fungi. This activator helps break down soil organic matter into organic compounds that are easily absorbed by plant roots. The composting was done by mixing kitchen and garden waste with the addition of EM4 and MOL. The fermentation process was carried out in variations of 10, 14, 21, 26, and 32 days. The results showed that the longer the fermentation time the better the compost was produced indicating by the leaves had crumbled into shape like the soil.</em></p>
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Wong, SC, and CB Osmond. "Elevated Atmosphere Partial Pressure of CO2 and Plant Growth. III. Interactions Between Triticum aestivum (C3) and Echinochloa frumentacea (C4) During Growth in Mixed Culture Under Different CO2, N Nutrition and Irradiance Treatments, With Emphasis on Below-Ground Responses Estimated Using the δ13C Value of Root Biomass." Functional Plant Biology 18, no. 2 (1991): 137. http://dx.doi.org/10.1071/pp9910137.
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Wheat (Triticum aestivum L.), a C3 species, and Japanese millet (Echinochloa frumentacea Link), a C4 species, were grown in pots in monoculture and mixed culture (2 C3 : 1 C4 and 1 C3:2 C4) at two ambient partial pressures of CO2 (320 and 640 μbar), two photosynthetic photon flux densities (PPFDs) (daily maximum 2000 and 500 �mol m-2 s-1) and two levels of nitrogen nutrition (12 mM and 2 mM NO3-). Growth of shoots of both components in mixed culture was measured by physical separation, and the proportions of root biomass due to each component were calculated from δ13C value of total root biomass. In air (320 μbar CO2) at high PPFD and with high root zone-N, the shoot biomass of C3 and C4 components at the first harvest (28 days) was in proportion to the sowing ratio. However, by the second harvest (36 days) the C4 component predominated in both mixtures. Under the same conditions, but with low PPFD, C3 plants predominated at the first harvest but C4 plants had over- taken them by the time of the second harvest. Elevated atmospheric CO2 (640 μbar) stimulated shoot growth of Triticum in 15 of 16 treatment combinations and the stimulation was greatest in plants provided with low NO3-. Root growth of the C3 plants was generally stimulated by elevated CO2, but was only occasionally sensitive to the presence of C4 plants in mixed culture. However, growth of the C4 plants was often sensitive to the presence of C3 plants in mixed culture. In mixed cultures, elevated CO2 plants stimulated growth of C4 plants at high PPFD, high-N and in all low-N treatments but this was insufficient to offset a marked decline in shoot growth with increasing proportion of C3 plants in mixed cultures. The unexpected stimulation of growth of C4 plants by elevated CO2 was correlated with more negative δ13C values of C4 root biomass, suggesting a partial failure of the CO2 concentrating mechanism of C4 photosynthesis in Echinochloa under low-N. These experiments show that for these species nitrogen was more important than light or elevated pCO2 in determining the extent of competitive interactions in mixed culture.
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Mašková, Petra, Barbora Radochová, Zuzana Lhotáková, Jan Michálek, and Helena Lipavská. "Nonstructural carbohydrate-balance response to long-term elevated CO2 exposure in European beech and Norway spruce mixed cultures: biochemical and ultrastructural responses." Canadian Journal of Forest Research 47, no. 11 (November 2017): 1488–94. http://dx.doi.org/10.1139/cjfr-2017-0083.
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Two dominant central European tree species (Fagus sylvatica L. and Picea abies (L.) Karst.), in a mixed culture in semi-open glass domes, were used to simulate the reaction of forests to long-term elevated CO2 (EC) in a mountainous area (Beskydy Mountains, the Czech Republic). We investigated the effects of EC on soluble carbohydrate levels and composition. Starch content was evaluated using two methods: biochemical (glucose content after enzymatic hydrolysis) and stereological (starch grain proportion, size, and number in chloroplasts). In beech and spruce foliage, no significant changes in total soluble carbohydrate levels were observed. In spruce, starch content determined biochemically increased under EC, whereas no changes were detected in beech. The starch content determined stereologically increased only in beech. In spruce, EC exposure caused comparable starch increases in current-year and previous-year needles, although the former had a higher starch content and numerous larger starch grains regardless of CO2 concentration. In both species, the biochemical determination of carbohydrates exhibited greater individual tree uniformity, in contrast to large intraspecies variability. No changes in leaf soluble carbohydrates under long-term elevated CO2 demonstrate the ability of the studied tree species to efficiently allocate the photosynthates among the sinks. Thus, no photosynthetic downregulation via carbohydrate-level signalling can be expected.
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Rajaii, Mahdieh, and Mehdi DahMardeh. "The Evaluation of Corn and Peanut Intercropping on Efficiency of Use the Environmental Resource and Soil Fertility." Journal of Agricultural Science 6, no. 4 (March 15, 2014): 99. http://dx.doi.org/10.5539/jas.v6n4p99.
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Order to study the effect of density, the control weed and various proportion corn (704 Variety) and peanut (Goli Variety) intercropping an experiment was conducted in 2012 in Research station of agriculture, University of Zabol. The experiment design was factorial in randomized complete block design with three replications. Experiment factors consisted of planting proportions in 4 levels (sole crop of corn, 50% corn + 50% peanut, 100% corn + 100% peanut and sole crop of peanut), control weed in 3 levels (non-weeding, once-weeding and twice-weeding) and the space between rows in 2 level (40 and 50 cm) has been considered. The evaluated Characteristics in environmental sources are (Photosynthetic Active Radiation, Temperature and soil Moisture), the nutrients of soil include (N, K, Na, Mg, Ca, and C) and to evaluate intercropping of pure was used land equivalent ratio and economical yield. All Characteristics of study were affected by planting system.There was significant interaction between planting system, weeding and density in the absorption of light, temperature and moisture of soil. The results showed that photosynthesis active radiation absorbed by the intercropping was higher than sole crop in both plants. The results showed that changes in soil nutrient capacity of single elements (Na and K) in the treatment of mixed and monoculture peanut was more than monoculture corn and divalent elements (Ca and Mg) in mixed and monoculture corn more than mixed replacement and peanut monoculture. The highest land equivalent ratio (1.048) was accounted additive intercropping. Generally the mixed cultures with increasing density and control weed caused increase soil fertility and amount of soil nutrients after harvest. Treatment 100% Corn +100% peanut was the best treatment because using sources and increasing soil fertility and crop yield in comparison to sole crop.
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Zagrodnik, Roman. "Optimization of Hydrogen Production by Co-Culture of Clostridium beijerinckii and Rhodobacter sphaeroides Bacteria." Advances in Science and Technology 93 (October 2014): 90–95. http://dx.doi.org/10.4028/www.scientific.net/ast.93.90.
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The biological methods of hydrogen generation have attracted a significant interest recently. In this work the hybrid system applying both dark fermentation bacteria in co-culture was tested. Objective of this work was to investigate the optimization of different parameters on co-culture of Clostridium beijerinckii DSM-791 and Rhodobacter sphaeroides O.U.001. The effect of glucose concentration (1–5 g/L), temperature and initial pH (6,5–7,5) was analyzed. Moreover the influence of organic nitrogen sources were tested for their capacity to support hydrogen production (yeast extract, peptone, glutamic acid). Fermentations were conducted in batch tests with glucose as sole substrate. Hydrogen production in mixed culture was compared with pure cultures. The process was greatly affected by pH and light/dark bacteria ratio. Liquid metabolites, namely acetic and butyric acids, from the dark fermentation step were the source of organic carbon for photosynthetic bacteria. This increased the hydrogen yield in comparison to single-step dark fermentation to over 4 mol H2/mol glucose. Obtained results showed that combination of photo and dark fermentation may increase hydrogen production and conversion efficiency of complex substrates or wastewaters.
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Sundstrom, Eric R., and Craig S. Criddle. "Optimization of Methanotrophic Growth and Production of Poly(3-Hydroxybutyrate) in a High-Throughput Microbioreactor System." Applied and Environmental Microbiology 81, no. 14 (May 8, 2015): 4767–73. http://dx.doi.org/10.1128/aem.00025-15.
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ABSTRACTProduction of poly(3-hydroxybutyrate) (P3HB) from methane has economic and environmental advantages over production by agricultural feedstock. Identification of high-productivity strains and optimal growth conditions is critical to efficient conversion of methane to polymer. Current culture conditions, including serum bottles, shake flasks, and agar plates, are labor-intensive and therefore insufficient for systematic screening and isolation. Gas chromatography, the standard method for analysis of P3HB content in bacterial biomass, is also incompatible with high-throughput screening. Growth in aerated microtiter plates coupled with a 96-well Nile red flow-cytometric assay creates an integrated microbioreactor system for high-throughput growth and analysis of P3HB-producing methanotrophic cultures, eliminating the need for individual manipulation of experimental replicates. This system was tested in practice to conduct medium optimization for P3HB production in pure cultures ofMethylocystis parvusOBBP. Optimization gave insight into unexpected interactions: for example, low calcium concentrations significantly enhanced P3HB production under nitrogen-limited conditions. Optimization of calcium and copper concentrations in the growth medium increased final P3HB content from 18.1% to 49.4% and P3HB concentration from 0.69 g/liter to 3.43 g/liter while reducing doubling time from 10.6 h to 8.6 h. The ability to culture and analyze thousands of replicates with high mass transfer in completely mixed culture promises to streamline medium optimization and allow the detection and isolation of highly productive strains. Applications for this system are numerous, encompassing analysis of biofuels and other lipid inclusions, as well as analysis of heterotrophic and photosynthetic systems.
Dissertations / Theses on the topic "Photosynthetic mixed cultures (PMC)"
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Fradinho, Joana Costa. "Polyhydroxyalkanoates production by photosynthetic mixed cultures." Doctoral thesis, 2013. http://hdl.handle.net/10362/16804.
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Polyhydroxyalkanoates (PHAs) are natural biologically synthesized polymers that have been the subject of much interest in the last decades due to their biodegradability. Thus far, its microbial production is associated with high operational costs, which increases PHA prices and limits its marketability. To address this situation, this thesis’ work proposes the utilization of photosynthetic mixed cultures (PMC) as a new PHA production system that may lead to a reduction in operational costs. In fact, the operational strategies developed in this work led to the selection of PHA accumulating PMCs that, unlike the traditional mixed microbial cultures, do not require aeration, thus permitting savings in this significant operational cost. In particular, the first PHA accumulating PMC tested in this work was selected under non-aerated illuminated conditions in a feast and famine regime, being obtained a consortium of bacteria and algae, where photosynthetic bacteria accumulated PHA during the feast phase and consumed it for growth during the famine phase, using the oxygen produced by algae. In this symbiotic system, a maximum PHA content of 20% cell dry weight (cdw) was reached, proving for the first time, the capacity of a PMC to accumulate PHA. During adaptation to dark/light alternating conditions, the culture decreased its algae content but maintained its viability, achieving a PHA content of 30% cdw. Also, the PMC was found to be able to utilize different volatile fatty acids for PHA production, accumulating up to 20% cdw of a PHA co-polymer composed of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (HV) monomers. Finally, a new selective approach for the enrichment of PMCs in PHA accumulating bacteria was tested. Instead of imposing a feast and famine regime, a permanent feast regime was used, thus selecting a PMC that was capable of simultaneously growing and accumulating PHA, being attained a maximum PHA content of 60% cdw, the highest value reported for a PMC thus far. The results presented in this thesis prospect the utilization of cheap, VFA-rich fermented wastes as substrates for PHA production, which combined with this new photosynthetic technology opens up the possibility for direct sunlight illumination, leading to a more cost-effective and environmentally sustainable PHA production process.
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Almeida, Juliana Roda. "Phototrophic bioplastic production from domestic and agro-industrial wastewaters." Master's thesis, 2017. http://hdl.handle.net/10362/24444.
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Polyhydroxyalkanoates (PHA), are a biodegradable polymer, naturally synthesized by several bacteria and with similar characteristics to conventional plastics. Recently, phototrophic PHA production has also been achieved in photosynthetic mixed cultures (PMCs) under an open, non-aerated and using direct sunlight system, lowering the operational costs commonly associated to the PHA production by pure and aerated mixed cultures. The photo-bioreactors (PBR) are also commonly used as wastewater (WW) treatment systems along with a consortium microalgae and bacteria communities. The main goals of this thesis were precisely to select a PHA accumulating PMC to achieve a new added-value bioproduct. The enrichment process of the PMC was performed by two different selection strategies - permanent feast regime and feast and famine regime - that were carried out under the same operational conditions of High Rate Algae Ponds (HRAPs) from Chiclana Wastewater Treatment Plant, using artificial illumination and fed with real wastewaters, establishing the effect of using wastewater on the culture growth and PHA production stability, and furthermore to evaluate the impact of operational conditions (OLR, pH, temperature and light intensity) on the PHA production performance of the system. This will be the first time that the PHA production through PMC will be tested at demonstration scale and using real wastewater.
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Pereira, Bruno Alexandre das Neves. "Effect of phosphate and sulphate loading rate on the selection of PHA accumulating phototrophic mixed cultures." Master's thesis, 2018. http://hdl.handle.net/10362/53896.
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Petroleum-based plastics have massively contributed to a substantial increase in environmental pollution. Biobased plastics have emerged as a much-needed alternative solution to fossil dependent synthetic polymers. Polyhydroxyalkanoates (PHA) are a promising group of biobased and biodegradable displaying similar features to conventional plastics. Their high-cost production has become a hindrance to its economical applicability. Alternative low-cost processes of production can be achieved by using renewable raw materials (as feedstock) combined with the use of mixed microbial cultures (MMCs).
Extensive research aiming the decrease of PHA production costs focused on the use of phototropic mixed cultures (PMC) enriched in purple bacteria is being developed (Fradinho et al. (2014)). The culture is selected under a feast and famine regime (FF) being able to reach up to 30% PHA / VSS using acetate as a carbon source in light/dark cycles. The permanent feast regime occurs as an alternative to the well-studied FF strategy and consists of a constant presence of carbon and the absence of electron acceptors. Ultimately, microorganisms such as purple bacteria will dissipate the reducing power (generated by the consumption of carbon source) and PHA will be formed. Using this strategy, Fradinho et al. (2016) obtained a 60% PHA/VSS content in a test with high light intensity. This work comes in the continuity of a previous study integrating a European project, NoAW, that aims for the valorisation of agro-industrial residues and for the production of valuable biobased products while exploring the phototrophic capacity of PMC under a permanent feast regime.
PMC selection was done in an SBR under 24h cycles (12h of light and 12h dark) operating in a continuous feeding mode during the light phase. The culture was fed synthetic medium composed of a mixture of volatile fatty acids (VFAs) simulating fermented waste of cow manure and maize silage. During the reactor operation, several operating conditions were tested and the most promising results were obtained under the double limitation of phosphorus and sulfur. A decrease in the amount of algae population (phototrophic organisms that do not produce PHA) was observed which contributed to a higher percentage of PHA production. Indeed, the culture attained a PHA content of 31% PHA / VSS (25 Cmmol/L) in accumulation tests with optimized light intensity and acetate as carbon source.
This highly attractive photosynthetic cultures’ ability opens new doors in its applicability in wastewater treatment plants (WWTP) that are under the direct illumination of sunlight. Wastewater could become a viable source of carbon for the production of valuable bioproducts, giving a highly desirable contribute to the implementation of a European circular economy.