Microcosm based analysis of arsenic release potential of Bacillus sp. strain IIIJ3-1 under varying redox conditions.
The role of indigenous bacteria in mobilization of sediment bound arsenic (As) into groundwater is investigated using subsurface sediment from Brahmaputra River Basin (BRB) and the Bacillus sp. strain IIIJ3-1, an indigenous species to BRB. Anaerobic sediment microcosms with varying organic carbon sources and terminal electron acceptors (TEAs) are used to illustrate the role of the test bacterium in As mobilization. The aquifer sediment shows an asymmetric distribution of As and Fe in its different phases. Among the TEAs added, NO3 amendment promotes higher cell growth, oxalic acid production and maximum release of sediment bound As. X-ray diffraction analysis further suggests that weathering of As bearing secondary minerals through bacterial action enhances As bioavailability, followed by dissimilatory reduction and thus promotes its mobilization into aqueous phase. Co-release pattern of other elements from the sediment indicates that release of As is decoupled from that of Fe. This study confirms that microbe-mediated mineral weathering followed by respiratory reduction of As facilitates mobilization of sediment hosted As into aqueous phase, and provides a better insight into the catabolic ability of groundwater bacteria in mobilization of sediment hosted As in BRB region.
['Ghosh|Soma|S|', 'Sar|Pinaki|P|http://orcid.org/0000-0001-6867-7817']
D001149:Arsenates D001151:Arsenic D001407:Bacillus D019015:Geologic Sediments D060587:Groundwater D007194:India D007501:Iron D064307:Microbiota D008903:Minerals D009566:Nitrates D019815:Oxalic Acid D010084:Oxidation-Reduction D045483:Rivers D014874:Water Pollutants, Chemical
Microcosm Bacillus sp. strain IIIJ3-1 As mobilization Bacterial oxalate production Decoupled release of As and Fe Nitrate