title: Arsenic biotransformation and release by bacteria indigenous to arsenic contaminated groundwater.
abstract: Arsenic (As) biotransformation and release by indigenous bacteria from As rich groundwater was investigated. Metabolic landscape of 173 bacterial isolates indicated broad catabolic repertoire including abundance of As(5+) reductase activity and abilities in utilizing wide ranges of organic and inorganic respiratory substrates. Abundance of As homeostasis genes and utilization of hydrocarbon as carbon/electron donor and As(5+) as electron acceptor were noted within the isolates. Sediment microcosm study (for 300 days) showed a pivotal role of metal reducing facultative anaerobic bacteria in toxic As(3+) release in aqueous phase. Inhabitant bacteria catalyze As transformation and facilitate its release through a cascade of reactions including mineral bioweathering and As(5+) and/or Fe(3+) reduction activities. Compared to anaerobic incubation with As(5+) reducing strains, oxic state and/or incubation with As(3+) oxidizing bacteria resulted in reduced As release, thus indicating a strong role of such condition or biocatalytic mechanism in controlling in situ As contamination.
authors.affiliation: Department of Biotechnology, Indian Institute of Technology, Kharagpur, 721302, India.
authors.forename: Dhiraj
authors.initials: D
authors.lastname: Paul
authors.affiliation: Department of Biotechnology, National Institute of Technology, Durgapur, 713209, India.
authors.forename: Sufia K
authors.initials: SK
authors.lastname: Kazy
authors.affiliation: Department of Biotechnology, National Institute of Technology, Durgapur, 713209, India.
authors.forename: Tirtha Das
authors.initials: TD
authors.lastname: Banerjee
authors.affiliation: Department of Civil Engineering, Indian Institute of Technology, Kharagpur, 721302, India.
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Gupta
authors.affiliation: Central Headquarters, Geological Survey of India, Kolkata 700016, India.
authors.forename: Taraknath
authors.initials: T
authors.lastname: Pal
authors.affiliation: Department of Biotechnology, Indian Institute of Technology, Kharagpur, 721302, India. Electronic address: psar@hijli.iitkgp.ernet.in.
authors.forename: Pinaki
authors.initials: P
authors.lastname: Sar
mesh_terms: D001151:Arsenic / Q000737:chemistry*; D001419:Bacteria / Q000378:metabolism*; D001711:Biotransformation; D002384:Catalysis; D060587:Groundwater / Q000382:microbiology*; D007287:Inorganic Chemicals / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D008024:Ligands; D009930:Organic Chemicals / Q000737:chemistry; D019815:Oxalic Acid / Q000737:chemistry; D010088:Oxidoreductases / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D025341:Principal Component Analysis; D012336:RNA, Ribosomal, 16S / Q000737:chemistry; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods
chemical_list: D007287:Inorganic Chemicals; D008024:Ligands; D009930:Organic Chemicals; D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical; D019815:Oxalic Acid; D007501:Iron; D010088:Oxidoreductases; D001151:Arsenic; D010100:Oxygen
keywords: Arsenic; As(3+) oxidation; As(5+) reduction; Bacteria; Microcosm