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Environmental Microbiology Reports Oct 2022
Topics: Anaerobiosis; Denitrification; Methane; Nitrites; Oxidation-Reduction
PubMed: 35944518
DOI: 10.1111/1758-2229.13114 -
Journal of Environmental Management Feb 2024A series of technologies have been employed in pilot-scale to process digestate, i.e. the byproduct remaining after the anaerobic digestion of agricultural and other...
A series of technologies have been employed in pilot-scale to process digestate, i.e. the byproduct remaining after the anaerobic digestion of agricultural and other wastes, with the aim of recovering nutrients and reducing the load of solids and organics from it, hence improving the quality of digestate for potential subsequent reuse. In this case the digestate originated from a mixture of dairy and animal wastes and a small amount of agricultural wastes. It was processed by the application of several treatments, applied in series, i.e. microfiltration, ultrafiltration, reverse osmosis, selective electrodialysis and combined UV/ozonation. The initially applied membrane filtration methods (micro- and ultra-filtration) removed most of the suspended solids and macromolecules with a combined efficiency of more than 80%, while the reverse osmosis (at the end) removed almost all the remaining solutes (85-100%), producing sufficiently clarified water, appropriate for potential reuse. In the selective electrodialysis unit over 95% of ammonium and potassium were recovered from the feed, along with 55% of the phosphates. Of the latter, 75% was retrieved in the form of struvite.
Topics: Animals; Anaerobiosis; Phosphates; Struvite; Ammonium Compounds; Nutrients
PubMed: 38280247
DOI: 10.1016/j.jenvman.2024.120166 -
International Journal of Environmental... Aug 2022Renewable energy source, such as food waste (FW), has drawn great attention globally due to the energy crisis and the environmental problem. Anaerobic digestion (AD)... (Review)
Review
Renewable energy source, such as food waste (FW), has drawn great attention globally due to the energy crisis and the environmental problem. Anaerobic digestion (AD) mediated by novel microbial consortia is widely used to convert FW to clean energy. Despite of the considerable progress on food waste and FWAD optimization condition in recent years, a comprehensive and predictive understanding of FWAD microbial consortia is absent and therefore represents a major research challenge in FWAD. The review begins with a global view on the FWAD status and is followed by an overview of the role of AD key conditions' association with microbial community variation during the three main energy substances (hydrogen, organic acids, and methane) production by FWAD. The following topic is the historical understanding of the FWAD microorganism through the development of molecular biotechnology, from classic strain isolation to low-throughput sequencing technologies, to high-throughput sequencing technologies, and to the combination of high-throughput sequencing and isotope tracing. Finally, the integration of multi-omics for better understanding of the microbial community activity and the synthetic biology for the manipulation of the functioning microbial consortia during the FWAD process are proposed. Understanding microbial consortia in FWAD helps us to better manage the global renewable energy source.
Topics: Anaerobiosis; Bioreactors; Food; Microbial Consortia; Refuse Disposal
PubMed: 35954875
DOI: 10.3390/ijerph19159519 -
Deutsches Arzteblatt International Nov 2019
Topics: Anaerobiosis; Comorbidity; Humans; Irritable Bowel Syndrome; Prevalence
PubMed: 31774055
DOI: 10.3238/arztebl.2019.0755a -
Sheng Wu Gong Cheng Xue Bao = Chinese... Dec 2022Anaerobic digestion is another important anaerobic catabolism pathway besides lactic acid and ethanol fermentation, which is of great significance for recycling...
Anaerobic digestion is another important anaerobic catabolism pathway besides lactic acid and ethanol fermentation, which is of great significance for recycling resources, maintaining the ecological balance, optimizing the energy structure, alleviating the energy crisis, and promoting the implementation of the "Carbon Peaking and Carbon Neutrality" strategy. However, such an important metabolic process has not been involved in the current textbooks and teaching of biochemistry courses, making the teaching system incomplete. The anaerobic digestion process involves many reactions and complex metabolic pathways. In order to improve the students' understanding to this process, we created a full chart of the whole anaerobic digestion process based on systemic literature review and integrated it into the classroom teaching through the BOPPPS teaching mode. It was found that the classroom teaching assisted by this metabolic chart could help students establish the structural framework of the anaerobic digestion process and enrich the knowledge system of metabolism, achieving a good teaching effect. This paper introduces the content of the metabolic pathways of anaerobic digestion and the design of the teaching process, which would facilitate the teaching reforms and perfection of textbooks for related courses, such as Biochemistry, Environmental Engineering Microbiology and New Energy Engineering.
Topics: Humans; Anaerobiosis; Biochemistry; Students; Metabolic Networks and Pathways; Fermentation
PubMed: 36593209
DOI: 10.13345/j.cjb.220305 -
Free Radical Biology & Medicine Aug 2019Eukaryotes arose about 1.6 billion years ago, at a time when oxygen levels were still very low on Earth, both in the atmosphere and in the ocean. According to newer... (Review)
Review
Eukaryotes arose about 1.6 billion years ago, at a time when oxygen levels were still very low on Earth, both in the atmosphere and in the ocean. According to newer geochemical data, oxygen rose to approximately its present atmospheric levels very late in evolution, perhaps as late as the origin of land plants (only about 450 million years ago). It is therefore natural that many lineages of eukaryotes harbor, and use, enzymes for oxygen-independent energy metabolism. This paper provides a concise overview of anaerobic energy metabolism in eukaryotes with a focus on anaerobic energy metabolism in mitochondria. We also address the widespread assumption that oxygen improves the overall energetic state of a cell. While it is true that ATP yield from glucose or amino acids is increased in the presence of oxygen, it is also true that the synthesis of biomass costs thirteen times more energy per cell in the presence of oxygen than in anoxic conditions. This is because in the reaction of cellular biomass with O, the equilibrium lies very far on the side of CO. The absence of oxygen offers energetic benefits of the same magnitude as the presence of oxygen. Anaerobic and low oxygen environments are ancient. During evolution, some eukaryotes have specialized to life in permanently oxic environments (life on land), other eukaryotes have remained specialized to low oxygen habitats. We suggest that the K of mitochondrial cytochrome c oxidase of 0.1-10 μM for O, which corresponds to about 0.04%-4% (avg. 0.4%) of present atmospheric O levels, reflects environmental O concentrations that existed at the time that the eukaryotes arose.
Topics: Anaerobiosis; Atmosphere; Biological Evolution; Energy Metabolism; Eukaryota; Mitochondria; Oxygen
PubMed: 30935869
DOI: 10.1016/j.freeradbiomed.2019.03.030 -
Scientific Reports Aug 2021The effect of nanobubbles on anaerobic growth and metabolism of Pseudomonas aeruginosa was investigated. P. aeruginosa grew earlier in the culture medium containing...
The effect of nanobubbles on anaerobic growth and metabolism of Pseudomonas aeruginosa was investigated. P. aeruginosa grew earlier in the culture medium containing nanobubbles and the bacterial cell concentration in that culture medium was increased a few times higher compared to the medium without nanobubbles under anaerobic condition. Both gas and protein, which are the metabolites of P. aeruginosa, were remarkably produced in the culture medium containing nanobubbles whereas those metabolites were little detected in the medium without nanobubbles, indicating nanobubbles activated anaerobic growth and metabolism of P. aeruginosa. The carbon dioxide nanobubbles came to be positively charged by adsorbing cations and delivered ferrous ions, one of the trace essential elements for bacterial growth, to the microbial cells, which activated the growth and metabolism of P. aeruginosa. The oxygen nanobubbles activated the activities of P. aeruginosa as an oxygen source.
Topics: Anaerobiosis; Culture Media; Nanoparticles; Pseudomonas aeruginosa; Sterilization
PubMed: 34413439
DOI: 10.1038/s41598-021-96503-4 -
Bioresource Technology Jun 2022The unprecedented demand for seafood has resulted in land-based recirculating aquaculture systems (RAS), a highly intensive but sustainable fish farming method. However,... (Review)
Review
The unprecedented demand for seafood has resulted in land-based recirculating aquaculture systems (RAS), a highly intensive but sustainable fish farming method. However, intensification also results in concentrated waste streams of fecal matter and uneaten feed. Harvesting and processing vast quantities of fish also leads to the production of byproducts, further creating disposal challenges for fish farms. Recent research indicates that anaerobic digestion (AD), often used for waste treatment in agricultural and wastewater industries, may provide a viable solution. Limited research on AD of freshwater, brackish, and saline wastewater from RAS facilities and co-digestion of seafood byproducts has shown promising results but with considerable operational and process stability issues. This review discusses challenges to AD due to low solid concentrations, salinity, low carbon/nitrogen ratio, and high lipid content in the waste streams. Opportunities for recovering valuable biomolecules and nutrients through microbial treatment, aquaponics, microalgae, and polyhydroxyalkanoate production are also discussed.
Topics: Anaerobiosis; Aquaculture; Nitrogen; Seafood; Wastewater
PubMed: 35413421
DOI: 10.1016/j.biortech.2022.127144 -
Journal of Clinical Microbiology May 2023
Review
Topics: Humans; Anaerobiosis; Staining and Labeling; Coloring Agents; Bacteria, Anaerobic
PubMed: 37219093
DOI: 10.1128/jcm.00150-22 -
Molecular Microbiology May 2008Historically many bacteria have been classified as obligate anaerobes. They have been construed as wholly intolerant of oxygen, a feature that was originally ascribed to...
Historically many bacteria have been classified as obligate anaerobes. They have been construed as wholly intolerant of oxygen, a feature that was originally ascribed to their lack of superoxide dismutases and catalases. Clostridial species were regarded as classic examples. We now know that this view is quite wrong: enzymes that scavenge superoxide, hydrogen peroxide and even oxygen itself abound in anaerobes. In the current issue of Molecular Microbiology, Hillmann et al. demonstrate that full production of these proteins can allow Clostridium acetobutylicum to survive and even grow in oxygenated culture medium. Evidently, oxidative defences in anaerobes can be robust. In all likelihood, they are critical for the movement of bacteria through aerobic environments to new anaerobic habitats.
Topics: Anaerobiosis; Clostridium acetobutylicum; Gene Expression Regulation, Bacterial; Oxidative Stress; Repressor Proteins
PubMed: 18363793
DOI: 10.1111/j.1365-2958.2008.06213.x