Literatura académica sobre el tema "Anaerobic growth conditions"
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Artículos de revistas sobre el tema "Anaerobic growth conditions"
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Wang, James C., Joehassin Cordero, Yan Sun, Mayank Aranke, Randall Wolcott, Jane A. Colmer-Hamood y Abdul N. Hamood. "Planktonic Growth ofPseudomonas aeruginosaaround a Dual-Species Biofilm Supports the Growth ofFusobacterium nucleatumwithin That Biofilm". International Journal of Otolaryngology 2017 (2017): 1–12. http://dx.doi.org/10.1155/2017/3037191.
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Purpose.The goal of this study was to understand the potential interaction betweenPseudomonas aeruginosaandFusobacterium nucleatumwithin the middle ear.Methods.We examined the microbiota of ear fluid and tympanostomy tubes (TTs) obtained from patients with posttympanostomy tube otorrhea. We also examined biofilms formed byP. aeruginosaandF. nucleatum, singly or together, under aerobic or anaerobic conditions.Results.While the facultative anaerobeP. aeruginosadominated the bacterial population within the ear fluid, strict anaerobes, includingF. nucleatum,dominated bacterial populations within the TTs.F. nucleatumwas able to grow under aerobic conditions only in the presence ofP. aeruginosa, whose growth reduced the level of dissolved oxygen within the broth to nearly anoxic condition within 4 h after inoculation. The presence ofP. aeruginosaallowedF. nucleatumto maintain its growth for 72 h within the dual-species biofilm but not within the planktonic growth. Visualization of the biofilms revealed coaggregation ofP. aeruginosaandF. nucleatum.Conclusion.Extrapolation of these results suggests that, within the middle ear fluid, the growth ofP. aeruginosaproduces the anaerobic conditions required for the growth ofF. nucleatum, both within effusion and within biofilms.
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Ye, Rick W., Wang Tao, Laura Bedzyk, Thomas Young, Mario Chen y Liao Li. "Global Gene Expression Profiles of Bacillus subtilis Grown under Anaerobic Conditions". Journal of Bacteriology 182, n.º 16 (15 de agosto de 2000): 4458–65. http://dx.doi.org/10.1128/jb.182.16.4458-4465.2000.
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ABSTRACT Bacillus subtilis can grow under anaerobic conditions, either with nitrate or nitrite as the electron acceptor or by fermentation. A DNA microarray containing 4,020 genes from this organism was constructed to explore anaerobic gene expression patterns on a genomic scale. When mRNA levels of aerobic and anaerobic cultures during exponential growth were compared, several hundred genes were observed to be induced or repressed under anaerobic conditions. These genes are involved in a variety of cell functions, including carbon metabolism, electron transport, iron uptake, antibiotic production, and stress response. Among the highly induced genes are not only those responsible for nitrate respiration and fermentation but also those of unknown function. Certain groups of genes were specifically regulated during anaerobic growth on nitrite, while others were primarily affected during fermentative growth, indicating a complex regulatory circuitry of anaerobic metabolism.
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Janssen, Peter H. "Growth of Enterobacteria on Malonate Under Strictly Anaerobic Conditions". Systematic and Applied Microbiology 14, n.º 1 (enero de 1991): 93–97. http://dx.doi.org/10.1016/s0723-2020(11)80367-x.
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Churchill, A. Coolidge. "Growth characteristics of Zostera marina seedlings under anaerobic conditions". Aquatic Botany 43, n.º 4 (noviembre de 1992): 379–92. http://dx.doi.org/10.1016/0304-3770(92)90049-o.
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Kelly, W. J., R. V. Asmundson y D. H. Hopcroft. "Growth ofLeuconostoc oenosunder Anaerobic Conditions". American Journal of Enology and Viticulture 40, n.º 4 (1989): 277–82. http://dx.doi.org/10.5344/ajev.1989.40.4.277.
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Lee, Hoyul, Rena Ma, Michael C. Grimm, Stephen M. Riordan, Ruiting Lan, Ling Zhong, Mark Raftery y Li Zhang. "Examination of the Anaerobic Growth ofCampylobacter concisusStrains". International Journal of Microbiology 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/476047.
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Campylobacter concisusis an oral bacterium that is associated with intestinal diseases.C. concisuswas previously described as a bacterium that requires H2-enriched microaerobic conditions for growth. The level of H2in the oral cavity is extremely low, suggesting thatC. concisusis unlikely to have a microaerobic growth there. In this study, the anaerobic growth ofC. concisuswas investigated. The growth of fifty-seven oralC. concisusstrains and six entericC. concisusstrains under various atmospheric conditions including anaerobic conditions with and without H2was examined. The atmospheric conditions were generated using commercially available gas-generation systems.C. concisusputative virulence proteins were identified using mass spectrometry analysis. Under anaerobic conditions, 92% of the oralC. concisusstrains (52/57) and all six enteric strains grew without the presence of H2and the presence of H2greatly increasedC. concisusgrowth. An oralC. concisusstrain was found to express a number of putative virulence proteins and the expression levels of these proteins were not affected by H2. The levels of H2appeared to affect the optimal growth ofC. concisus. This study provides useful information in understanding the natural colonization site and pathogenicity ofC. concisus.
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McCaughey, Gerard, Deirdre F. Gilpin, Thamarai Schneiders, Lucas R. Hoffman, Matt McKevitt, J. Stuart Elborn y Michael M. Tunney. "Fosfomycin and Tobramycin in Combination Downregulate Nitrate Reductase GenesnarGandnarH, Resulting in Increased Activity against Pseudomonas aeruginosa under Anaerobic Conditions". Antimicrobial Agents and Chemotherapy 57, n.º 11 (19 de agosto de 2013): 5406–14. http://dx.doi.org/10.1128/aac.00750-13.
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ABSTRACTThe activity of aminoglycosides, which are used to treatPseudomonas aeruginosarespiratory infection in cystic fibrosis (CF) patients, is reduced under the anaerobic conditions that reflect the CF lungin vivo. In contrast, a 4:1 (wt/wt) combination of fosfomycin and tobramycin (F:T), which is under investigation for use in the treatment of CF lung infection, has increased activity againstP. aeruginosaunder anaerobic conditions. The aim of this study was to elucidate the mechanisms underlying the increased activity of F:T under anaerobic conditions. Microarray analysis was used to identify the transcriptional basis of increased F:T activity under anaerobic conditions, and key findings were confirmed by microbiological tests, including nitrate utilization assays, growth curves, and susceptibility testing. Notably, growth in subinhibitory concentrations of F:T, but not tobramycin or fosfomycin alone, significantly downregulated (P< 0.05) nitrate reductase genesnarGandnarH, which are essential for normal anaerobic growth ofP. aeruginosa. Under anaerobic conditions, F:T significantly decreased (P< 0.001) nitrate utilization inP. aeruginosastrains PAO1, PA14, and PA14lasR::Gm, a mutant known to exhibit increased nitrate utilization. A similar effect was observed with two clinicalP. aeruginosaisolates. Growth curves indicate that nitrate reductase transposon mutants had reduced growth under anaerobic conditions, with these mutants also having increased susceptibility to F:T compared to the wild type under similar conditions. The results of this study suggest that downregulation of nitrate reductase genes resulting in reduced nitrate utilization is the mechanism underlying the increased activity of F:T under anaerobic conditions.
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Liu, Zihe, Tobias Österlund, Jin Hou, Dina Petranovic y Jens Nielsen. "Anaerobic α-Amylase Production and Secretion with Fumarate as the Final Electron Acceptor in Saccharomyces cerevisiae". Applied and Environmental Microbiology 79, n.º 9 (22 de febrero de 2013): 2962–67. http://dx.doi.org/10.1128/aem.03207-12.
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ABSTRACTIn this study, we focus on production of heterologous α-amylase in the yeastSaccharomyces cerevisiaeunder anaerobic conditions. We compare the metabolic fluxes and transcriptional regulation under aerobic and anaerobic conditions, with the objective of identifying the final electron acceptor for protein folding under anaerobic conditions. We find that yeast produces more amylase under anaerobic conditions than under aerobic conditions, and we propose a model for electron transfer under anaerobic conditions. According to our model, during protein folding the electrons from the endoplasmic reticulum are transferred to fumarate as the final electron acceptor. This model is supported by findings that the addition of fumarate under anaerobic (but not aerobic) conditions improves cell growth, specifically in the α-amylase-producing strain, in which it is not used as a carbon source. Our results provide a model for the molecular mechanism of anaerobic protein secretion using fumarate as the final electron acceptor, which may allow for further engineering of yeast for improved protein secretion under anaerobic growth conditions.
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BELAY, NEGASH y AVRAHAM RASOOLY. "Staphylococcus aureus Growth and Enterotoxin A Production in an Anaerobic Environment". Journal of Food Protection 65, n.º 1 (1 de enero de 2002): 199–204. http://dx.doi.org/10.4315/0362-028x-65.1.199.
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The effects of strict anaerobic conditions on the growth of Staphylococcus aureus and the production of staphylococcal enterotoxin A (SEA) were studied. The growth of S. aureus, a facultative anaerobic bacterium, is slower anaerobically than aerobically. When grown on brain heart infusion broth at 37°C, the anaerobic generation time at mid-log phase was 80 min, compared with 35 min for the aerobic control. In contrast to previous studies demonstrating that staphylococcal cell density was 9- to 17-fold greater in aerobic than in anaerobic cultures, data for a staphylococcal strain implicated in food poisoning showed that the cell density was only two to three times as great in aerobic cultures. Production of SEA was monitored by Western immunoblotting and shown to be growth dependent. With slower anaerobic growth, relatively less toxin was produced than under aerobic conditions, but in both cases SEA was detected after 120 min of incubation. The combined effects of temperature and aeration on S. aureus were also studied. Growth and toxin production of aerobic and anaerobic cultures at temperatures ranging from 14 to 37°C were analyzed. Growth was still observed at low temperatures in both environments. A linear model for S. aureus aerobic or anaerobic growth as a function of incubation temperature was developed from these studies. The model was tested from 17 to 35.5°C, and the results suggest that the model can accurately predict the S. aureus growth rate in this temperature range. The data suggest that anaerobic conditions are not an effective barrier against S. aureus growth.
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Michel, Andrea, Abigail Koch-Koerfges, Karin Krumbach, Melanie Brocker y Michael Bott. "Anaerobic Growth of Corynebacterium glutamicum via Mixed-Acid Fermentation". Applied and Environmental Microbiology 81, n.º 21 (14 de agosto de 2015): 7496–508. http://dx.doi.org/10.1128/aem.02413-15.
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ABSTRACTCorynebacterium glutamicum, a model organism in microbial biotechnology, is known to metabolize glucose under oxygen-deprived conditions tol-lactate, succinate, and acetate without significant growth. This property is exploited for efficient production of lactate and succinate. Our detailed analysis revealed that marginal growth takes place under anaerobic conditions with glucose, fructose, sucrose, or ribose as a carbon and energy source but not with gluconate, pyruvate, lactate, propionate, or acetate. Supplementation of glucose minimal medium with tryptone strongly enhanced growth up to a final optical density at 600 nm (OD600) of 12, whereas tryptone alone did not allow growth. Amino acids with a high ATP demand for biosynthesis and amino acids of the glutamate family were particularly important for growth stimulation, indicating ATP limitation and a restricted carbon flux into the oxidative tricarboxylic acid cycle toward 2-oxoglutarate. Anaerobic cultivation in a bioreactor with constant nitrogen flushing disclosed that CO2is required to achieve maximal growth and that the pH tolerance is reduced compared to that under aerobic conditions, reflecting a decreased capability for pH homeostasis. Continued growth under anaerobic conditions indicated the absence of an oxygen-requiring reaction that is essential for biomass formation. The results provide an improved understanding of the physiology ofC. glutamicumunder anaerobic conditions.
Tesis sobre el tema "Anaerobic growth conditions"
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Beckhouse, Anthony Gordon Biotechnology & Biomolecular Sciences Faculty of Science UNSW. "The transcriptional and physiological alterations in brewers yeast when shifted from anaerobic to aerobic growth conditions". Awarded by:University of New South Wales. School of Biotechnology and Biomolecular Sciences, 2006. http://handle.unsw.edu.au/1959.4/24201.
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Yeast are exposed to many physical and chemical stresses when used in large-scale industrial fermentations, particularly the initial stages in which yeast are shifted from anaerobic storage to aerated wort. This work investigated the transcriptional and physiological responses of yeast that had been shifted from anaerobic to aerobic growth conditions. Microarray technology was employed to determine the transcriptional changes that occurred in the first hour of a pilot-plant fermentation compared to the 23rd hour. It was found that over 100 genes were up-regulated initially including genes involved in the synthesis of the essential membrane sterol ergosterol and genes for the protection of cells against oxidative stress. It was also determined that cells which accumulate ergosterol precursors in the absence of ergosterol were more sensitive to exogenous oxidative stresses, indicating a role for ergosterol in oxidative stress tolerance. Aeration of anaerobically grown cells did not affect their growth kinetics or viability. However, anaerobically grown cells were hypersensitive to exogenous oxidative stress compared to their aerobic counterparts. Anaerobic cells that underwent a short period of aeration prior to treatment with hydrogen peroxide generated a tolerance to the oxidant, indicating that the period of aeration produced an adaptive-like response. Microarray analysis of the cells during the period of aeration showed that representative genes from the oxidative stress response family were up-regulated rapidly and it was determined that the response was controlled by the Yap1p and Skn7p transcription factors. Deletion of the transcription factor genes indicated that they were responsible for the creation of tolerance to oxidant. Target gene products of the two transcription factors (Gpx2p, Gsh1p and Trx2p) were shown to be induced during the shift to aeration; however, the glutathione redox balance did not seem to be affected as the cells were shifted from highly reduced to oxidising environments. Unexpectedly, it was discovered that genes involved in the synthesis of amino acids were up-regulated during anaerobic growth and stringently downregulated upon aeration of cells. The transcriptional activator of those genes (Gcn4p) was essential for growth in anaerobic media which included amino acid supplementation.
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Golbach, Jennifer L. "Development of a rapid riboflavin growth-based assay using Lactobacillus rhamnosus". Texas A&M University, 2005. http://hdl.handle.net/1969.1/3131.
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Riboflavin is an essential part of the human diet. Although the United States
does not have a major problem with a riboflavin deficiency, other regions of the world
do. This is especially true for those regions whose main subsistence is rice. To help
prevent and control riboflavin deficiencies, many cereal grains are now being fortified
with riboflavin. The recommended dietary allowance of riboflavin is 1.1-1.6 mg per day.
This value increases slightly for pregnant women, breast feeding women, and athletes.
Because riboflavin is an essential part of the diet, it is important to ensure that the
minimum requirements for this nutrient are met. By determining the amount of
riboflavin in food products, an accurate estimate of daily riboflavin intake can be
determined. The AOAC (Association of Official Analytical Chemists) approved
microbiological riboflavin assay can be tedious and time consuming. A faster approach
to the riboflavin assay would greatly benefit the food industry. By scaling down the
assay to microtiter plates both, time and materials can be conserved. Use of microtiter
plates would also allow for numerous samples to be assayed simultaneously. The goal
for developing the microtiter plate assay is to obtain results more rapidly while
maintaining the accuracy and precision of the AOAC ( method 940.33I) tube assay.
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Peksel, Begum. "Proteome Analysis Of Hydrogen Production Mechanism Of Rhodobacter Capsulatus Grown On Different Growth Conditions". Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614133/index.pdf.
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Rhodobacter capsulatus is a versatile organism capable of growing on different growth conditions including photofermentation in the presence of carbon source, aerobic respiration, anaerobic respiration in the presence of an external electron acceptor such as DMSO. The photofermentative growth of R.capsulatus results in hydrogen production which stands out as an environmentally harmless method to produce hydrogen and accepted as one of the most promising process. Due to the serious problems such as as global climate change and environmental pollution caused by the fossil fuels, there is an increasing requirement for a clean and sustainable energy source. Furtherrmore, the ability of R.capsulatus to fix nitrogen, to use solar energy makes it a model to study various aspects of its metabolism. Thus the goal of this study is to increase the potential in biohydrogen production with the photofermentative bacteria and to investigate the proteins playing roles in different growth modes of the bacteria.
In the present study, protein profiles of Rhodobacter capsulatus grown on respiratory, anaerobic respiratory and photofermentative growth modes were obtained. LC-MS/MS system is used to analyze the proteome as a high throughput technique. Physiological analysis such as HPLC for the analysis of the carbon source consumption, GC and analysis of pigments were carried out to state the environmental conditions. As a result, total of 460 proteins were identified with 17 proteins being unique to particular growth condition. Ratios of the proteins in different growth conditions were compared and important proteins were highlighted.
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MUZZIOTTI, GIL DAYANA ISABEL. "Physiological response of the anoxygenic photosynthetic bacterium Rhodopseudomonas palustris 42OL to high light intensity". Doctoral thesis, 2016. http://hdl.handle.net/2158/1028530.
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This thesis is constituted of an introductive section given detailed information about the metabolic versatility of purple non sulfur bacteria. An exhaustive description of the photo-fermentation process in purple non sulfur bacteria is also offered, with particular consideration to the conditions needed to produce hydrogen. The acclimation (chromo-acclimation) to high light intensities in purple non sulfur bacteria is detailed described, and the role of photo-pigments into this process is highly considered. Moreover, a short description of all ways to dissipate the excess of energy by photosynthetic organisms, is included in this introduction. The use of different techniques to understand the molecular/ energetic status of the photosynthetic unit is presented, with particular attention to Pulse- Amplitude- modulation (PAM) fluorescence and Saturation Pulse Method of Quenching Analysis. In this section, a general view regarding the inhomogeneity problems of light distribution during the photo- fermentation process using purple non sulfur bacteria is offered. Furthermore, short statements about one topic with a few references in literature is described, i.e. production of hydrogen as a way to discard the excess of reducing power generated as a result of high light intensities exposure. The main aim of this thesis was to study the behavior of the purple non sulfur bacterium Rhodopseudomonas palustris strain 42OL to different culturing conditions illuminated at high light intensities, with particular interest to the production of hydrogen as a way to dispose the excess of reductants and as a mechanism to preserve a well physiological status. Besides, the acclimation to high light intensities in this strain was also one of the main objectives to be studied, particularly the trend of photo- pigments.
Capítulos de libros sobre el tema "Anaerobic growth conditions"
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Maciorowski, K. G., D. J. Nisbet, S. D. Ha, D. E. Corrier, J. R. DeLoach y S. C. Ricke. "Fermentation and Growth Response of a Primary Poultry Isolate of Salmonella Typhimurium Grown under Strict Anaerobic Conditions in Continuous Culture and Amino Acid-Limited Batch Culture". En Advances in Experimental Medicine and Biology, 201–8. Boston, MA: Springer US, 1997. http://dx.doi.org/10.1007/978-1-4899-1828-4_29.
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Goddek, Simon, Alyssa Joyce, Sven Wuertz, Oliver Körner, Ingo Bläser, Michael Reuter y Karel J. Keesman. "Decoupled Aquaponics Systems". En Aquaponics Food Production Systems, 201–29. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-15943-6_8.
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AbstractTraditional aquaponics systems were arranged in a single process loop that directs nutrient-rich water from fish to the plants and back. Given the differing specific nutrient and environmental requirements of plants and fish, such systems presented a compromise to the ideal conditions for rearing of both, thus reducing the efficiency and productivity of such coupled systems. More recently, designs that allow for decoupling of units provide for a more finely tuned regulation of the process water in each of the respective units while also allowing for better recycling of nutrients from sludge. Suspended solids from the fish (e.g. faeces and uneaten feed) need to be removed from the process water before water can be directed to plants in order to prevent clogging of hydroponic systems, a step that represents a significant loss of total nutrients, most importantly phosphorus. The reuse of sludge and mobilization of nutrients contained within that sludge present a number of engineering challenges that, if addressed creatively, can dramatically increase the efficiency and sustainability of aquaponics systems. One solution is to separate, or when there are pathogens or production problems, to isolate components of the system, thus maximizing overall control and efficiency of each component, while reducing compromises between the conditions and species-specific requirements of each subsystem. Another potential innovation that is made possible by the decoupling of units involves introducing additional loops wherein bioreactors can be used to treat sludge. An additional distillation loop can ensure increased nutrient concentrations to the hydroponics unit while, at the same time, reducing adverse effects on fish health from high nutrient levels in the RAS unit. Several studies have documented the aerobic and anaerobic digestion performance of bioreactors for treating sludge, but the benefits of the digestate on plant growth are not well-researched. Both remineralization and distillation components consequently have a high unexplored potential to improve decoupled aquaponics systems.
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Tandoi, V., M. Beccari, R. Ramadori y L. Sebastiani Annicchiarico. "ACINETOBACTER SP GROWTH IN ALTERNATE ANAEROBIC–AEROBIC CONDITIONS". En Biological Phosphate Removal from Wastewaters, 305–8. Elsevier, 1987. http://dx.doi.org/10.1016/b978-0-08-035592-4.50032-8.
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Hassan, Siti Roshayu Binti, Mohamad Johari Abu y Irvan Dahlan. "Industrial Wastewater Treatment". En Handbook of Research on Resource Management for Pollution and Waste Treatment, 318–38. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-0369-0.ch014.
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The development of effective and simple methods for treating wastewater is a challenging task for environmental engineers. In this chapter, a novel modified anaerobic hybridized baffled (MAHB) bioreactor, which is a combination of regular suspended-growth and fixed biofilm systems together with the modification of baffled-reactor configurations, was proven to be a modest bioreactor for wastewater treatment rather than the commercial anaerobic baffled reactor (ABR). The significant advantages of this bioreactor were its ability to nearly realize the multi-stages anaerobic theory, allowing different bacterial groups to develop under more favourable conditions, reduced sludge bed expansion, no special gas or sludge separation required, and high stability to organic and toxic shock loads. The compartmentalization of this bioreactor results in a buffering zone between the primary acidification zone and active methanogenesis zone, and provided the strong ability to resist shock loads which broaden the usage of multi-phase anaerobic technology for industrial wastewater treatment.
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Ohmura, Naoya, Norio Matsumoto, Kazuhiro Sasaki, Toru Nagaoka y Hiroshi Saiki. "Growth of Thiobacillus ferrooxidans on hydrogen by the dissimilatory reduction of ferric iron under anaerobic conditions". En Biohydrometallurgy and the Environment Toward the Mining of the 21st Century - Proceedings of the International Biohydrometallurgy Symposium, 767–75. Elsevier, 1999. http://dx.doi.org/10.1016/s1572-4409(99)80079-0.
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Ashraf, Naira y Moieza Ashraf. "Response of Growth Inhibitor Paclobutrazol in Fruit Crops". En Prunus. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.92883.
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Paclobutrazol (PBZ; IUPAC name: (2RS, 3RS)-1-(4-chlorophenyl)-4, 4-dimethyl-2-(1H-1, 2, 4-triazol-1-yl) pentan-3-ol) is a triazol derivative and an antagonist of gibberellins. It has been shown to inhibit shoot growth in various perennial fruit trees. Paclobutrazol application reduced the number of shoots, transforming trees into a more desirable, spur-type growth habit as the vegetative sink was reduced. This compound induces an early and intense flowering, diminishing vegetative growth and reducing the extension of buds, allowing for ripening and the initiation of apical buds inflorescence. Besides, it also increases fruit set, the years following application as a carryover effect. An increase in return bloom is a common response to paclobutrazol treatment and has been reported for various fruit crops. Paclobutrazol is widely used to advance harvest maturity in various fruit crops and it improves fruit quality in terms of accelerated colour development, delayed and synchronized fruit maturation and control of preharvest fruit drop. It is known to improve fruit physical and fruit chemical characteristics. Fruit calcium is increased for 2–3 years due to carry over effect. It helps in the maintenance of better fruit quality during storage and influences nutrient uptake in various fruit crops including stone fruits. It has been characterized as an environmentally stable compound in soil and water environments with a long half-life under both aerobic and anaerobic conditions.
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P. Smith, Daniel y Nathaniel T. Smith. "Solanum tuberosum Cultivation Using Nitrogen Recovered from Local Wastewater". En Solanum tuberosum - a Promising Crop for Starvation Problem [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.98554.
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This chapter presents an approach to recover nitrogen from human waste-water at local-scale for cultivation of Solanum tuberosum (potato) as food crop. Nitrogen capture is by ion exchange of ammonium (NH4+) onto zeolite, a natural low cost mineral which is available worldwide. A coupled process is described in which wastewater ammonium is sorbed to granular zeolite, biologically extracted (desorbed), and used to support Solanum tuberosum growth in fill-and-drain or irrigation cultivation. The system employs separate components to optimize conditions for ammonium sorption (anaerobic ion exchange), desorption (aerobic bioextraction), and cultivation (flexible timing of water and nitrogen supply and nutrient recycle). System architecture provides a low cost and readily implemented system for highly efficient nitrogen capture and incorporation into potato tuber. The nitrogen recycle system enables sustainable local-scale intensification of Solanum tuberosum production and enhanced food security through use of a reliable local nutrient supply. Metrics are presented for per capita tuber production, land area, and productivity. A system design is presented with a path forward for demonstration and development.
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Kumar Tiwary, Bipransh y Masrure Alam. "Extremophiles: An Overview". En Extremophiles: Diversity, Adaptation and Applications, 1–23. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9789815080353122010005.
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Earth contains several environmental extremes which are uninhabitable for most of the living beings. But, astonishingly, in the last few decades, several organisms thriving in such extreme environments have been discovered. “Extremophiles”, meaning “Lovers of Extremities” are the entities that are especially adapted to live in such harsh environmental conditions in which other entities cannot live. The discovery of extremophiles has not only boosted the biotech industry to search for new products from them, but also made researchers to think for the existence of extra-terrestrial life. The most inhospitable environments include physical or chemical extremities, like high or low temperatures, radiation, high pressure, water scarcity, high salinity, pH extremes, and limitation of oxygen. Microorganisms have been found to live in all such environmental conditions, like hyperthermophiles and psychrophiles, acidophiles and alkaliphiles. Bacteria like Deinococcus radiodurans, which is able to withstand extreme gamma radiation, and Moritella sp., able to grow at atmospheric pressure of >1000 atm, have been reported. Environments like the Dead Sea, having saturated NaCl concentrations, hold extreme halophiles like Halobacterium salinarum. Highly acidic environments, like the Rio-Tinto River in Spain or Danakil depression in Ethiopia harbour acidophiles with growth optima of pH zero, or close to it. Bacillus alcalophilus, and Microcystis aeruginosa on the other hand inhabit natural alkaline soda lakes where pH can reach about 12.0. A number of anaerobic prokaryotes can live in complete anoxic environments by using terminal electron acceptors other than oxygen. In this chapter, we shall discuss very briefly the diversity of all extremophiles and their mechanism(s) of adaptation.
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Dolphin, Heather y Fatima Ahmad. "Bacteriology Diagnostic Methods". En Tutorial Topics in Infection for the Combined Infection Training Programme. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198801740.003.0015.
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This is summarized in Table 8.1. a) Microscopy— A cell count is performed on sterile fluids and CSF samples using the Neubauer chamber or a similar device. The number of white blood cells (WBC) and red blood cells seen under the microscope are reported as well as the differential WBC count (i.e. the number or percentage of lymphocytes and neutrophils in the sample). A Gram stain is then done and the presence of any organism reported. b) Culture samples are plated onto the appropriate media and streaked out for single colonies as shown. Blood agar is normally used; however, other media are used depending on the site of the specimen, e.g. chocolate agar is used if a fastidious organism is a potential pathogen such as Haemophilus sp.; anaerobic agar for anaerobes; selective agar such as MacConkey can be used on non-sterile specimens to differentiate between the colony types. Plates are incubated for eighteen to forty-eight hours at the correct conditions; most plates being CO2, others at O2 and anaerobically. c) Identification plates are examined for growth. Potentially significant isolates are identified either by MALDI-TOF MS, by API, or other biochemical tests. d) Sensitivities are performed on significant organisms by manual and automated methods. This is summarized in Table 8.2. Selective agar is necessary when isolating pathogens from faeces, although further confirmatory tests are needed. ● Black or colourless colonies on xylose lysine deoxycholate (XLD) or other chromogenic agar plates are tested with oxidase reagent. ● Oxidase negative isolates are identified by MALDI-TOF, API and or biochemically using triple-sugar iron (TSI) tubes. ● Serology is then performed on suspicious isolates and sent to a reference laboratory for confirmation. ● Campylobacter is confirmed by testing grey flat colonies on campylobacter agar with oxidase reagent. Oxidase positive samples are Gram stained and if ‘seagull’-shaped gram-negative bacteria are observed under the microscope, campylobacter is confirmed. The catalase test is a simple biochemical test to differentiate between Staphylococcus species and Streptococcus species, with the use of hydrogen peroxide (H2O2). It tests for the presence of the enzyme catalase which is found in Staphylococcus species.
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Tsutsumi, Yutaka. "Pathology of Gangrene". En Pathogenic Bacteria. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.93505.
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Pathological features of gangrene are described. Gangrene is commonly caused by infection of anaerobic bacteria. Dry gangrene belongs to noninfectious gangrene. The hypoxic/ischemic condition accelerates the growth of anaerobic bacteria and extensive necrosis of the involved tissue. Clostridial and non-clostridial gangrene provokes gas formation in the necrotic tissue. Acute gangrenous inflammation happens in a variety of tissues and organs, including the vermiform appendix, gallbladder, bile duct, lung, and eyeball. Emphysematous (gas-forming) infection such as emphysematous pyelonephritis may be provoked by Escherichia coli and Klebsiella pneumoniae. Rapidly progressive gangrene of the extremities (so-called “flesh-eating bacteria” infection) is seen in fulminant streptococcal, Vibrio vulnificus, and Aeromonas hydrophila infections. Fournier gangrene is an aggressive and life-threatening gangrenous disease seen in the scrotum and rectum. Necrotizing fasciitis is a subacute form of gangrene of the extremities. Of note is the fact that clostridial and streptococcal infections in the internal organs may result in a lethal hypercytokinemic state without association of gangrene of the arms and legs. Uncontrolled diabetes mellitus may play an important role for vulnerability of the infectious diseases. Pseudomonas-induced malignant otitis externa and craniofacial mucormycosis are special forms of the lethal gangrenous disorder.
Actas de conferencias sobre el tema "Anaerobic growth conditions"
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Teh, Kwee-Yan. "Thermodynamic Analysis of Fermentation and Anaerobic Growth of Baker’s Yeast". En ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-10401.
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Thermodynamic concepts have been used in the past to predict microbial cell yield under various growth conditions. Cell yield may be the key consideration in some industrial biotechnology applications. It is not the case, however, in the context of biofuel production. In this paper, we examine the thermodynamics of fermentation and concomitant growth of baker’s yeast in continuous culture experiments under anaerobic, glucose-limited conditions, with emphasis on the yield and efficiency of ethanol production. We find that anaerobic metabolism of baker’s yeast is very efficient; the process destroys less than 7% of the total chemical exergy supplied to the fermentation reactor. However, the exergy of ethanol secreted constitutes less than 60% of the in-flowing exergy, or 75% that of glucose fed to the continuous culture. Effects of varying the specific adenosine 5′-triphosphate (ATP) consumption rate, which is the fundamental parameter that quantifies the energetic requirements for cell growth and maintenance, are also examined.
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Sabliy, Larisa, Veronika Zhukova y Lyubov Kika. "Effective Biological Treatment of Tannery Wastewater from Nitrogen Compounds". En The 9th International Conference on Advanced Materials and Systems. INCDTP - Leather and Footwear Research Institute (ICPI), Bucharest, Romania, 2022. http://dx.doi.org/10.24264/icams-2022.ii.22.
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Even after using physico-chemical and biological methods, tannery wastewater still contains a large amount of nitrogen compounds, which reaches 90 mg/dm3. The ingress of such wastewater into natural reservoirs leads to eutrophication. The goal is to determine the efficiency of nitrogen compounds removal during sequential wastewater treatment in anaerobic, anoxic and aerobic bioreactors with immobilized microorganisms. For the study, wastewater from a tannery, collected after cleaning in aeration tanks, was used. Model solutions with a concentration of 18.4 - 90 mg/ dm3 were obtained by dilution. 5 sequential bioreactors were used - anaerobic (2 stages), anoxic (2 stages) and aerobic (1 stage) with a capacity of 125 ml/h. Microorganisms were immobilized in each bioreactor on artificial carrier. The effects of organic nitrogen removal in anaerobic bioreactors were 58-66%, anoxic 51-70%, aerobic 57, 5%. A decrease in the concentration of nitrogen compounds occurs as a result of the formation of N2, NH3 gases and the use of nitrogen by microorganisms for biomass growth. It is proposed that sequential treatment of tannery wastewater in anaerobic, anoxic, and aerobic conditions with immobilized microorganisms made it possible to obtain a high degree of nitrogen removal. The method does not require chemical materials and is ecological.
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Chai Ching Hsia, Ivy, Mohd Firdaus Abdul Wahab, Nur Kamilah Abdul Jalil, Abigail Harriet Goodman, Hazratul Mumtaz Lahuri y Sahriza Salwani Md Shah. "Accelerated Methanogenesis for the Conversion of Biomethane from Carbon Dioxide and Biohydrogen at Hyperthermophilic Condition". En International Petroleum Technology Conference. IPTC, 2023. http://dx.doi.org/10.2523/iptc-22744-ea.
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Abstract Methanogenesis is the conversion of carbon dioxide (CO2) to methane (CH4) using microbes. In the context CO2 utilization, methanogenesis process in the utilizing native microbes from a particular reservoir can be a very slow process without any external intervention. To accelerate the conversion rate and methane yield, this study investigates the use of agriculture by-product such as palm oil mill effluent (POME) as substrates as well as potential microbial isolates that can produce biohydrogen at high temperatures. This paper covers the three laboratory assessments of microbes from anaerobic sludge from a local palm oil mill, use of POME to augment the microbial growth, and physicochemical manipulation to identify key parameters that increases CH4 yield and rate: i) biohydrogen production ii) biomethane production, and iii) syntrophic reactions. All experiments are conducted at 70°C which is considered a hyperthermophilic condition for many microbes. Biohydrogen production achieved with highest H2 production of 66.00 (mL/Lmedium). For biomethane production, the highest production rate achieved was 0.0768 CH4 µmol/mL/day which 10,000X higher than 19.6 pmol/mL/day used as a benchmark. Syntrophic reaction with both types of hydrogen-producing and methanogen in the same reactor, and pure H2 and CO2 supplemented externally was able to achieve the highest methane production of 10.095 µmol/mL and 2.524 µmol/ml/day. Methane production rate is 2.5 times faster than without external gasses being introduced. Introduction of external CO2 to the syntrophic reaction is to mimic actual carbon injection and storage in the reservoir. Our paper shows that stimulation of microbes using POME as substrates and H2/CO2 supplementation are important in accelerating the rate of methane production and yield. Future work will focus on optimizing the gas ratio, pH of growth media, and performing syntrophic reaction in porous media to emulate conditions of a reservoir.
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Ito, Miu y Yuichi Sugai. "Study on Enhanced Oil Recovery Using Microorganism Generating Foam in Presence of Nanobubbles". En SPE/IATMI Asia Pacific Oil & Gas Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/205671-ms.
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Abstract Both high cost and environmental load of surfactant are issues to be solved in foam EOR. Moreover, it is difficult to control the injection of surfactant and gas so that the foam is generated in only high permeable zones selectively in oil reservoir. The authors have found a foam generating microorganism and hit upon an idea of the microbial foam EOR which makes the microorganism do generating foam in oil reservoir. The mechanism of the microbial foam generation and culture condition suitable for the foam generation were studied in this study. A species of Pseudomonas aeruginosa was used as a foam producer in this study. It was cultured in the medium consisting of glucose and eight kinds of minerals at 30 °C and atmospheric pressure under anaerobic conditions. Because P. aeruginosa generally grows better under aerobic conditions, the microorganism was supplied with oxygen nanobubbles as the oxygen source. The carbon dioxide nanobubbles were also used as a comparison target in this study. The state of foam generation in the culture solution was observed during the cultivation. The surface tension, surfactant concentration, protein concentration, polysaccharides concentration and bacterial population of the culture solution were measured respectively. The foam was started to be generated by the microorganism after 2 days of cultivation and its volume became maximum after 3 days of cultivation. The foam generation was found in the culture solution which contained both oxygen nanobubbles and carbon dioxide nanobubbles whereas little foam was found in non-nanobubbles culture solution. The foam generation found in the culture solution containing carbon dioxide nanobubbles was more than that in the culture solution containing oxygen nanobubbles. Both gas and protein concentration increased along with the formation of the foam whereas surfactant and polysaccharides were not increased, therefore, the foam was assumed to be generated with gas and protein which were generated by P. aeruginosa. It was found that the carbon dioxide nanobubbles were positively charged in the culture medium whereas they were negatively charged in tap water through the measurement of zeta potential of nanobubbles, therefore, the carbon dioxide nanobubbles attracted cations in the culture medium and became positively charged. Positively charged carbon dioxide nanobubbles transported cations to the microbial cells of P. aeruginosa. Among cations in the culture medium, ferrous ions are essential for the protein generation of P. aeruginosa, therefore, the positively charged carbon dioxide nanobubbles attracted ferrous ions and transport them to the microbial cells, resulting the growth and metabolism of P. aeruginosa were activated. Those results suggest that the microbial foam EOR can be materialized by supplying the microorganism with carbon dioxide nanobubbles or ferrous ions.
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Men, Hong, Yan Peng, Jing Zhang, Shanrang Yang y Zhiming Xu. "Study on Biocorrosion Induced by Sulfate-Reducing Bacteria on Heat Exchanger Material in Cooling Water". En 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22747.
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Corrosion associated with microorganisms has been recognized for over 50 years and yet the study of microbiologically influenced corrosion (MIC) is relatively new. MIC can occur in diverse environments. Industrial cooling water from rivers, lakes and sea water contain lots of microorganisms which are able to grow and multiply under certain conditions when pH, water temperature and sunlight etc are suitable. MIC is one of key cause of heat exchanger faults. MIC of heat exchanger materials in cooling waters has caused expensive unplanned outages, the need for local repairs and, in some cases, completes system replacement. Sulfate-reducing bacteria (SRB) are the main harmful bacteria in circulating cooling water. Under anaerobic conditions, SRB reproduce a lot to produce mucus, which speed up the formation of corrosion, erode the metal equipment, plug the pipeline, affect the efficiency of heat transfer, and bring a lot of inconvenience to the production. The corrosion behaviors of 304 stainless steel induced by SRB were studied by measuring the polarization curves, electrochemical impedance Spectrum, weight loss measurements of fore-and-aft biocorrosion, and electrochemical noise method. The electrochemical noise signal of 304 stainless steel corrosion were de-noised by using a wavelet threshold de-noising method, which made the quadratic biorthogonal spline wavelet as the mother wavelet and adopted an soft threshold processing function. The result showed that the slope of cathodic polarization curves measured included with SRB is lower than the one obtained without SRB, while the slope of anodic polarization curves is higher than it. It is concluded that the process of anode polarization was repressed at the presence of SRB. With the growth of the culture time, the value of electrochemical impedance without bacteria reduced at first, then rose, while with bacteria fell at all times. It indicated that SRB accelerated the corrosion of stainless steel. With the dipping time, a biofilm, under which corrosion products congregate to form local battery corrosion, was formed on the surface of stainless steel, so that the serious pitting corrosion is induced. The results from electrochemical noise method showed that the quadratic biorthogonal spline wavelet much smoother and it can remove the noise from the electrochemical noise effectively, and can effectively identify the location of the sudden changes in the signal and accurately reflect the useful information of the signal. The more useful information and data about biocorrosion induced by SRB are also gotten.
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Liu, Songyuan, Bo Lu, Chao-yu Sie y Yifan Li. "Bioremediation by Indigenous Microbes: A Green Approach to Degrade Polymer Residue". En SPE Improved Oil Recovery Conference. SPE, 2022. http://dx.doi.org/10.2118/209422-ms.
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Abstract Polyacrylamide-based friction reducer is commonly used in well completion for unconventional reservoirs. However, residual polymer trapped in the near well-bore region could create unintended flow restrictions and could negatively impact oil production. An eco-friendly approach to regain conductivity was developed by stimulating indigenous bacteria for residual polymer biodegradation. In this work, a series of laboratory experiments were conducted using produced water and oil from Permian Basin, polyacrylamide-based polymer, and a modified nutrient recipe that contained 100 to 300 ppm of inorganic salts. The sealed sample vials containing water, oil, and polymer were prepared in a sterilized anaerobic chamber and then kept in a 160° F incubator to simulate the reservoir condition. Feasibility tests of bacteria growth and biodegradation evaluation of polymer were conducted using an optical laser microscopic system with bacteria tagged with fluorescent dye. Size regression was calculated and applied to a mathematical model based on actual fracture aperture distribution data from shale formation. The indigenous bacteria were successfully stimulated with and without the existence of the friction reducer. It was observed that the size of polymer particles decreased from over 300 µm to less than 20 µm after 15 days. Under the condition of produced water injection, 140° F reservoir temperature, and anaerobic environment, about 30% of the natural fractures in shale were calculated to be damaged and remediated within 15 days. This work is a pioneer research on microbial EOR application in unconventional reservoirs with only indigenous bacteria involved. In field applications, only an extremely low amount of nutrient is required in this process which provides great economic potential. Additionally, the nutrients introduced into the reservoirs will be fully consumed by bacteria during treatment, and the bacteria will be decomposed into organic molecules soon after the treatment. Thus, this technique is environmental- and economical- friendly for the purpose of polymer damage remediation to maximize the recoverable.
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Kopecký, Marek, Jaroslav Bernas, Ladislav Kolář y Pavlína Hloucalová. "MONITORING OF ENERGY GAIN AND EROSION PROTECTION OF CORN AND TALL WHEATGRASS CROPS IN THE CONDITIONS OF THE CZECH REPUBLIC". En RURAL DEVELOPMENT. Aleksandras Stulginskis University, 2018. http://dx.doi.org/10.15544/rd.2017.084.
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With the growing energy demand of the society and the increased requirements for ecological aspects of obtaining and utilizing energies, renewable energy sources have been getting to the forefront. In the conditions of Central Europe, transformation of biomass to biogas through anaerobic digestion appears to be promising. The article describes the results of a field experiment carried out in an experimental site of the University of South Bohemia in České Budějovice (South Bohemia, Czech Republic). The goal of the article is to compare the conventionally grown corn (Zea mays L., hybrid Simao), the areas of which have increased considerably as a result of the development of biogas stations, and the alternative perennial grass called tall wheatgrass (Elymus elongatus subsp. ponticus cv. Szarvasi-1), which is, according to the literature, well positioned to replace corn. The harvests of the plants took place in 2013-2015, and tall wheatgrass was cut twice per season. A number of aspects – dry phytomass yield, specific methane yield and hectare methane yield – were monitored. In addition, the long-term soil loss by water erosion was calculated through the Universal Soil Loss Equation for both species of energy crops. In terms of yield parameters and methane production, better results were achieved by corn, given the average energy gain 238 GJ·ha-1 as compared to 126 GJ·ha-1 for tall wheatgrass. The protection of the soil surface from water erosion by corn appears to be insufficient and, in this criterion, it absolutely lags behind the anti-erosion abilities of tall wheatgrass, which protects soil incomparably better.
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Straka, Luboslav y Tibor Krenicky. "TRANSFORMATION OF HIGH-DENSITY GREEN ENERGY WITH SIMULTANEOUS DECONTAMINATION OF THE ENVIRONMENT". En GEOLINKS Conference Proceedings. Saima Consult Ltd, 2021. http://dx.doi.org/10.32008/geolinks2021/b2/v3/43.
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In recent years, there has been an increased emphasis worldwide on the quality of the environment, especially with an orientation towards the application of renewable energy sources. In addition, we are increasingly encountering experimentation aimed at obtaining new green energy sources. One of such sources is biomass. Biomass has been used since the middle ages as a source of heat and light energy. Today, however, we have technologies that allow us to obtain not only heat but also electricity from biomass, or to convert biomass into materials with high energy density and purity. The energy thus transformed can then be used, for example, as a propellant. At the same time, this valuable source of clean energy can be easily transported to the place of consumption. By applying biomass as a source of green energy, we can make a significant contribution to relieving the environment from harmful effects. In recent years, an increased interest in energy obtained from biomass can be observed in Slovakia. Its technical potential is the greatest among other renewable energy sources, and its non-use would essentially be wastage. Therefore, the aim of the paper was to describe two possibilities of transformation of biomass in the form of its energy recovery into the type of energy used for the production of mechanical, thermal and electrical energy. At the same time, in addition to obtaining a suitable form of energy from biomass, another environmental benefit was sought in the form of soil decontamination. In this regard, there is an energetically important crop, which is known under the Latin name Amaranthus caudatus. It is an energy crop that can be grown on slightly contaminated soil with some restrictions. Two methods of energy recovery of this crop were compared. In the first case it was its compaction into briquettes, in the second case it was a process of anaerobic fermentation with subsequent production of biogas. Based on the performed analysis, it was found that these are almost equivalent energy sources. Although both methods of transformation and energy recovery of the green part of Amaranthus caudatus crops have a number of advantages and disadvantages, it can be clearly stated that the positives significantly outweigh the negatives. Therefore, it is recommended to apply this crop as a valuable source of energy for use in real conditions.
Informes sobre el tema "Anaerobic growth conditions"
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Van Rijn, Jaap, Harold Schreier y Yossi Tal. Anaerobic ammonia oxidation as a novel approach for water treatment in marine and freshwater aquaculture recirculating systems. United States Department of Agriculture, diciembre de 2006. http://dx.doi.org/10.32747/2006.7696511.bard.
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Ammonia waste removal in recirculating aquaculture systems is typically accomplished via the action of nitrifying bacteria in specially designed biofilters that oxidize ammonia to produce nitrate. In the majority of these systems nitrate is discharged to the environment through frequent water exchanges. As environmental considerations have made it necessary to eliminate nitrate release, new strategies for nitrate consumption are being developed. In the funding period we showed that ammonia removal from wastewater could take place by an anaerobic ammonia oxidation process carried out by bacterial Planctomycetessp. Referred to as “anammox”, this process occurs in the absence of an organic source and in the presence of nitrite (or nitrate) as an electron acceptor as follows: NH₃ + HNO₂ -> N₂ + 2H₂O. Annamox has been estimated to result in savings of up to 90% of the costs associated with was wastewater treatment plants. Our objective was to study the applicability of the anammox process in a variety of recirculating aquaculture systems to determine optimal conditions necessary for efficient ammonia waste removal. Both seawater and freshwater systems operated with either conventional aerobic treatment of ammonia to nitrate (USA) or, in addition, denitrifying biofilters as well as anaerobic digestion of sludge (Israel) were tested. Molecular tools were used to screen and monitor different treatment compartments for the presence of Planctomycetes. Optimal conditions for the enrichment of the anammox bacteria were tested using laboratory scale biofilters as well as a semi-commercial system. Enrichment studies resulted in the isolation of some unique heterotrophic bacteria capable of plasmid-mediated autotrophic growth in the presence of ammonia and nitrite. Our studies have not only demonstrated the presence and viability of Planctomycetes spp. in recirculating marine and freshwater systems biofilter units but also demonstrated the applicability of the anammox process in these systems. Using our results we have developed treatment schemes that have allowed for optimizing the anammox process and applying it to recirculating systems.
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Halevy, Orna, Sandra Velleman y Shlomo Yahav. Early post-hatch thermal stress effects on broiler muscle development and performance. United States Department of Agriculture, enero de 2013. http://dx.doi.org/10.32747/2013.7597933.bard.
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In broilers, the immediate post-hatch handling period exposes chicks to cold or hot thermal stress, with potentially harmful consequences to product quantity and quality that could threaten poultry meat marketability as a healthy, low-fat food. This lower performance includes adverse effects on muscle growth and damage to muscle structure (e.g., less protein and more fat deposition). A leading candidate for mediating the effects of thermal stress on muscle growth and development is a unique group of skeletal muscle cells known as adult myoblasts (satellite cells). Satellite cells are multipotential stem cells that can be stimulated to follow other developmental pathways, especially adipogenesis in lieu of muscle formation. They are most active during the first week of age in broilers and have been shown to be sensitive to environmental conditions and nutritional status. The hypothesis of the present study was that immediate post-hatch thermal stress would harm broiler growth and performance. In particular, growth characteristics and gene expression of muscle progenitor cells (i.e., satellite cells) will be affected, leading to increased fat deposition, resulting in long-term changes in muscle structure and a reduction in meat yield. The in vitro studies on cultured satellite cells derived from different muscle, have demonstrated that, anaerobic pectoralis major satellite cells are more predisposed to adipogenic conversion and more sensitive during myogenic proliferation and differentiation than aerobic biceps femoris cells when challenged to both hot and cold thermal stress. These results corroborated the in vivo studies, establishing that chronic heat exposure of broiler chicks at their first two week of life leads to impaired myogenicity of the satellite cells, and increased fat deposition in the muscle. Moreover, chronic exposure of chicks to inaccurate temperature, in particular to heat vs. cold, during their early posthatch periods has long-term effects of BW, absolute muscle growth and muscle morphology and meat quality. The latter is manifested by higher lipid and collagen deposition and may lead to the white striping occurrence. The results of this study emphasize the high sensitivity of muscle progenitor cells in the early posthatch period at a time when they are highly active and therefore the importance of rearing broiler chicks under accurate ambient temperatures. From an agricultural point of view, this research clearly demonstrates the immediate and long-term adverse effects on broiler muscling and fat formation due to chronic exposure to hot stress vs. cold temperatures at early age posthatch. These findings will aid in developing management strategies to improve broiler performance in Israel and the USA. BARD Report - Project4592 Page 2 of 29
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Minz, Dror, Stefan J. Green, Noa Sela, Yitzhak Hadar, Janet Jansson y Steven Lindow. Soil and rhizosphere microbiome response to treated waste water irrigation. United States Department of Agriculture, enero de 2013. http://dx.doi.org/10.32747/2013.7598153.bard.
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Research objectives : Identify genetic potential and community structure of soil and rhizosphere microbial community structure as affected by treated wastewater (TWW) irrigation. This objective was achieved through the examination soil and rhizosphere microbial communities of plants irrigated with fresh water (FW) and TWW. Genomic DNA extracted from soil and rhizosphere samples (Minz laboratory) was processed for DNA-based shotgun metagenome sequencing (Green laboratory). High-throughput bioinformatics was performed to compare both taxonomic and functional gene (and pathway) differences between sample types (treatment and location). Identify metabolic pathways induced or repressed by TWW irrigation. To accomplish this objective, shotgun metatranscriptome (RNA-based) sequencing was performed. Expressed genes and pathways were compared to identify significantly differentially expressed features between rhizosphere communities of plants irrigated with FW and TWW. Identify microbial gene functions and pathways affected by TWW irrigation*. To accomplish this objective, we will perform a metaproteome comparison between rhizosphere communities of plants irrigated with FW and TWW and selected soil microbial activities. Integration and evaluation of microbial community function in relation to its structure and genetic potential, and to infer the in situ physiology and function of microbial communities in soil and rhizospere under FW and TWW irrigation regimes. This objective is ongoing due to the need for extensive bioinformatics analysis. As a result of the capabilities of the new PI, we have also been characterizing the transcriptome of the plant roots as affected by the TWW irrigation and comparing the function of the plants to that of the microbiome. *This original objective was not achieved in the course of this study due to technical issues, especially the need to replace the American PIs during the project. However, the fact we were able to analyze more than one plant system as a result of the abilities of the new American PI strengthened the power of the conclusions derived from studies for the 1ˢᵗ and 2ⁿᵈ objectives. Background: As the world population grows, more urban waste is discharged to the environment, and fresh water sources are being polluted. Developing and industrial countries are increasing the use of wastewater and treated wastewater (TWW) for agriculture practice, thus turning the waste product into a valuable resource. Wastewater supplies a year- round reliable source of nutrient-rich water. Despite continuing enhancements in TWW quality, TWW irrigation can still result in unexplained and undesirable effects on crops. In part, these undesirable effects may be attributed to, among other factors, to the effects of TWW on the plant microbiome. Previous studies, including our own, have presented the TWW effect on soil microbial activity and community composition. To the best of our knowledge, however, no comprehensive study yet has been conducted on the microbial population associated BARD Report - Project 4662 Page 2 of 16 BARD Report - Project 4662 Page 3 of 16 with plant roots irrigated with TWW – a critical information gap. In this work, we characterize the effect of TWW irrigation on root-associated microbial community structure and function by using the most innovative tools available in analyzing bacterial community- a combination of microbial marker gene amplicon sequencing, microbial shotunmetagenomics (DNA-based total community and gene content characterization), microbial metatranscriptomics (RNA-based total community and gene content characterization), and plant host transcriptome response. At the core of this research, a mesocosm experiment was conducted to study and characterize the effect of TWW irrigation on tomato and lettuce plants. A focus of this study was on the plant roots, their associated microbial communities, and on the functional activities of plant root-associated microbial communities. We have found that TWW irrigation changes both the soil and root microbial community composition, and that the shift in the plant root microbiome associated with different irrigation was as significant as the changes caused by the plant host or soil type. The change in microbial community structure was accompanied by changes in the microbial community-wide functional potential (i.e., gene content of the entire microbial community, as determined through shotgun metagenome sequencing). The relative abundance of many genes was significantly different in TWW irrigated root microbiome relative to FW-irrigated root microbial communities. For example, the relative abundance of genes encoding for transporters increased in TWW-irrigated roots increased relative to FW-irrigated roots. Similarly, the relative abundance of genes linked to potassium efflux, respiratory systems and nitrogen metabolism were elevated in TWW irrigated roots when compared to FW-irrigated roots. The increased relative abundance of denitrifying genes in TWW systems relative FW systems, suggests that TWW-irrigated roots are more anaerobic compare to FW irrigated root. These gene functional data are consistent with geochemical measurements made from these systems. Specifically, the TWW irrigated soils had higher pH, total organic compound (TOC), sodium, potassium and electric conductivity values in comparison to FW soils. Thus, the root microbiome genetic functional potential can be correlated with pH, TOC and EC values and these factors must take part in the shaping the root microbiome. The expressed functions, as found by the metatranscriptome analysis, revealed many genes that increase in TWW-irrigated plant root microbial population relative to those in the FW-irrigated plants. The most substantial (and significant) were sodium-proton antiporters and Na(+)-translocatingNADH-quinoneoxidoreductase (NQR). The latter protein uses the cell respiratory machinery to harness redox force and convert the energy for efflux of sodium. As the roots and their microbiomes are exposed to the same environmental conditions, it was previously hypothesized that understanding the soil and rhizospheremicrobiome response will shed light on natural processes in these niches. This study demonstrate how newly available tools can better define complex processes and their downstream consequences, such as irrigation with water from different qualities, and to identify primary cues sensed by the plant host irrigated with TWW. From an agricultural perspective, many common practices are complicated processes with many ‘moving parts’, and are hard to characterize and predict. Multiple edaphic and microbial factors are involved, and these can react to many environmental cues. These complex systems are in turn affected by plant growth and exudation, and associated features such as irrigation, fertilization and use of pesticides. However, the combination of shotgun metagenomics, microbial shotgun metatranscriptomics, plant transcriptomics, and physical measurement of soil characteristics provides a mechanism for integrating data from highly complex agricultural systems to eventually provide for plant physiological response prediction and monitoring. BARD Report