title: Shifts in microbial community in response to dissolved oxygen levels in activated sludge.
abstract: This study evaluates the degradative efficiency of activated biomass collected from a Common Effluent Treatment Plant (CETP) under three different dissolved oxygen (DO) levels, 1, 2 and 4mgl(-1). The change in bacterial diversity with reference to DO levels was also analyzed. Results demonstrate that degradative efficiency was the highest, when the reactor was maintained at 4mgl(-1) DO, but amplicon library analysis showed a greater diversity of bacteria in the reactor maintained at 2mgl(-1) DO. Bacteria belonging to the order Desulfuromonadales, Entomoplasmatales, Pasteurellales, Thermales and Chloroflexales have only been detected in this reactor. Ammonia and nitrate levels in all three reactors indicated efficient nitrification process. Results of this study offer new insights into understanding the performance of activated biomass vis-à-vis microbial diversity and degradative efficiency with reference to DO. This information would be useful in improving the efficiency of any wastewater treatment plant.
authors.affiliation: Environmental Genomics Division, National Environmental Engineering Research Institute (CSIR-NEERI), Nagpur 440020, India.
authors.forename: Trilok Chandra
authors.initials: TC
authors.lastname: Yadav
authors.affiliation: Environmental Genomics Division, National Environmental Engineering Research Institute (CSIR-NEERI), Nagpur 440020, India.
authors.forename: Anshuman A
authors.initials: AA
authors.lastname: Khardenavis
authors.affiliation: Environmental Genomics Division, National Environmental Engineering Research Institute (CSIR-NEERI), Nagpur 440020, India. Electronic address: a_kapley@neeri.res.in.
authors.forename: Atya
authors.initials: A
authors.lastname: Kapley
mesh_terms: D000641:Ammonia / Q000032:analysis; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D001673:Biodegradation, Environmental; D044822:Biodiversity; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology; D064307:Microbiota / Q000187:drug effects*; D009566:Nitrates / Q000032:analysis; D010100:Oxygen / Q000494:pharmacology*; D010802:Phylogeny; D025341:Principal Component Analysis; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology*; D012995:Solubility; D013045:Species Specificity; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000382:microbiology; D018508:Water Purification
chemical_list: D000641:Ammonia; D009566:Nitrates; D010100:Oxygen; D012722:Sewage; D062065:Wastewater
keywords: Activated biomass; Amplicon library; Dissolved oxygen; Microbial diversity; Wastewater treatment