Phylogenetic Analysis of Anaerobic Co-Digestion of Animal Manure and Corn Stover Reveals Linkages between Bacterial Communities and Digestion Performance

Over 3 million tons of manures are produced annually in the United States and pose environmental and health risks if not remediated. Anaerobic digestion is an effective method in treating organic wastes to reduce environmental impacts and produce methane as an alternative energy. Previous studies suggested that optimization of feed composition, hydraulic retention time, and other operational conditions can greatly improve total solids removal and increase methane productivity. These environmental factors improve functionality by altering the microbial community structure but explicit details of how the bacterial community shifts are poorly understood. Our investigations were conducted to investigate the relationship between environmental factors, microbial community structure and bioreactor efficiency by using metagenomic analysis of the microbial communities. Our results indicated that the bioreactor with the greatest methane production, digestion efficiency and reduced levels of E. coli/Shigella had a distinctive community structure at the genus level with unique and abundant uncultivated strains of Bacteroidetes. Moreover the same bioreactor was enriched in Aminomonas paucivorans and Clostridia populations that can utilize secondary metabolites produced during cellulose/hemicellulose degradation to generate hydrogen and acetate. Hence specific digestion conditions that enrich for these populations may provide a route to the optimization of co-digestion systems and control the variability in reactor performance.

Biodegradation of resorcinol by Pseudomonas sp.

Objective:To investigate the ability of Pseudomonas sp.isolated from East Azarbaijan,Iran in bioremediation of resorcinol.Methods:Resorcinol biodegradation was evaluated using spectrophotometry and confirmed by gas chromatography-mass spectroscopy.Results:This isolate was able to remove up to 37.12%of resorcinol from contaminated water.Reusability experiments had confirmed the biodegradation process which produced seven intermediate compounds.These intermediates were characterized by gas chromatography-mass spectroscopy technique.The products of resorcinol biodegradation were apparently 1,4-cyclohexadiene,nonadecene,2-heptadecanone,1-isopropyl-2-methoxy-4-methylbenzene,hexadecanoic acid,9-octadecenoic acid,phenol and 5-methyl-2-(1-methylethyl).Conclusions:The findings revealed that Pseudomonas sp.is able to degrade resorcinol.Because of being an indigenous organism,this isolate is more compatible with the climate of the northwest region of Iran and possibly will be used for degradation of other similar aromatic compounds.

Microbial communication during bioremediation of polyaromatic hydrocarbons

Human activity pollution has been shown to harm the environment,ecology,and health impacts.The polycyclic aromatic hydrocarbons(PAHs)produced by the industries such as tannery,distillery,pulp paper,and oil refineries are a major source of contaminant.PAHs are found all across the world,owing to long-term human pollution sources.PAHs'physico-chemical features,such as hydrophobicity and electrochemical stability,contribute to their environmental persistence and contribute to their carcinogenic and health effects.Numerous analytical and biological techniques for the qualitative and quantitative assessment of PAHs have been proposed.Bioaccumulation,adsorption,chemical oxidation,photolysis,volatilization,and microbiological degradation are the principal breakdown pathways of PAHs in the environment.Microbial populations,such as bacteria,fungi,and algae,play a crucial role in the biological elimination of PAHs.Oxidase,manganese peroxidases,lipases,and laccases are the enzymes involved in PAHs breakdown.The synthesis of surfactants by bacteria increases PAHs bioavailability and improves the elimination process of PAHs.Temperature,pH,aeration,moisture content,nutrition availability,absence of hazardous chemicals,and the kind and number of degrading microbial populations are all factors that influence PAHs decomposition.Microbial degradation mechanisms result in intermediate metabolites and carbon dioxide mineralization.The elimination of PAHs is improved by molecular approaches such as gene engineering and protein engineering.This review discussed the benefits of bioremediation strategies that were investigated for precise evaluation and were trusted at both the regulatory and scientific studies levels.