title: Molecular analysis of microbial community in arsenic-rich groundwater of Kolsor, West Bengal.
abstract: Bacterial community composition within the highly arsenic (As) contaminated groundwater from Kolsur, West Bengal was analyzed over a period of 3 years using 16S rRNA gene clone library and Denaturing Gradient Gel Electrophoresis (DGGE). Molecular phylogenetic study revealed abundance of α-Proteobacteria (56%) and Firmicutes (29%) along with members of β-Proteobacteria, Verrucomicrobia and Sphingobacteria as relatively minor groups. Along with consistent physicochemical environment, a stable microbial community structure comprising of bacterial genera Agrobacterium-Rhizobium, Ochrobactrum, Pseudomonas, Anoxybacillus and Penibacillus was recorded over the three years study period. Presence of cytosolic arsenate reductase (arsC) gene was observed within the microbial community. Phylogenetic analyses revealed that all the arsC sequences were closely related to the same gene from γ-proteobacterial members while the community was consisted of mainly α-proteobacterial groups. Such phylogenetic incongruence between 16S rRNA and arsC genes possibly indicated horizontal gene transfer (HGT) of the ars genes within the groundwater community. Overall, the study reported a nearly stable geomicrobial environment and genetic determinant related to As homeostasis gene, and provided a better insight on biogeochemistry of As contaminated aquifer of West Bengal.
authors.affiliation: a Department of Biotechnology , Indian Institute of Technology Kharagpur , India.
authors.forename: Angana
authors.initials: A
authors.lastname: Sarkar
authors.affiliation: a Department of Biotechnology , Indian Institute of Technology Kharagpur , India.
authors.forename: Dhiraj
authors.initials: D
authors.lastname: Paul
authors.affiliation: b Department of Biotechnology , National Institute of Technology Durgapur , India.
authors.forename: Sufia K
authors.initials: SK
authors.lastname: Kazy
authors.affiliation: a Department of Biotechnology , Indian Institute of Technology Kharagpur , India.
authors.forename: Pinaki
authors.initials: P
authors.lastname: Sar
mesh_terms: D001151:Arsenic / Q000032:analysis* / Q000378:metabolism; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D060587:Groundwater / Q000737:chemistry / Q000382:microbiology*; D007194:India; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
chemical_list: D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical; D001151:Arsenic
keywords: 16S rRNA gene; ARDRA; Arsenic; DGGE; arsC; bacterial community