Extreme halophilic archaea Halobacterium sp. SP1 in bioremediation of hypersaline water polluted with metal, metalloid, organometal and aromatic compound

Abstract

Extremely halophilic rod shaped, motile prokaryotic microorganism was isolated from sediment of Ribandar salt pan, Goa, India on NTYE agar (25% crude salt) with 500 units/mL penicillin and was designated as SP1. By performing antibiotic sensitivity test, sodium taurocholate sensitivity test, cell lysis in distilled water, glycerol diether lipid moieties in membrane, spectrophotometric analysis of carotenoid pigment and biochemical tests, the isolates SP1 was confirmed to be extreme haloarchaea Halobacterium sp. Extremely haloarchaeal isolate, Halobacterium sp. SP1 could resist 50 muM HgCl2 in NGSM broth with 0.1mM MIC (minimum inhibitory concentration). The isolate showed the potential of reducing soluble, toxic selenite into less toxic, insoluble elemental selenium (Se sup(0)) which is indicated by change in colony color from red to bright orange. The isolate showed selenite reduction to elemental selenium up to 10 mM with MIC 11 mM. Halobacterium sp. SP1 could degrade up to 1.5 mM sodium benzoate as sole source of carbon on NSM broth (25 percent crude salt) and showed 2 mM MIC. Halobacterium sp. SP1 can also capable of utilizing up to 1 mM tributyltin chloride (TBTCl) having 2 mM MIC on NTYE (25 percent crude salt) agar. Haloarchaea Halobacterium sp. SP1 is multi extremophilic archaea i.e. resistant/degrading multiple pollutants (Hg, Se, sodium benzoate and TBTCl) in hypersaline conditions and is of great importance for bioremediation of hypersaline environments contaminated with multiple pollutants. This is first report of haloarchea Halobacterium sp. resistant to multiple pollutants such as metal, metalloid, organometal and aromatic compound in hypersaline environment.