Isolation and characterization of arsenic resistant bacterial strian Kurthia gibsonii MKVVM3 IITBHU from Ganga river

Abstract An arsenite-oxidizing bacterium was isolated from the Ganga River, Varanasi, India. Phylogenetic analysis by 16S rRNA gene sequencing identified the isolated strain as Kurthia gibsonii MKVVM3 IITBHU. The bacterial growth showed biofilm formation in the As (V) containing growth medium. The strain oxidized 100 mg l −1 of As (III) to As (V) in the initial 24 h of incubation. In the first two days, the arsenite oxidase gene amplified by Kurthia gibsonii MKVVM3 IITBHU lowered arsenic levels up to 95%. As (V) reductase gene expression present in the Kurthia gibsonii MKVVM3 IITBHU was involved in the conversion of As (V) into more soluble As (III). The isolate was short rods and it ranged from 500 to 1900 nm in length and 352.3 to 519.8 nm in width. The differences in pre and post As exposed Kurthia gibsonii MKVVM3 IITBHU in the Amide I area were linked to peptide bonds, C–H and C=O stretchings. These variations reflected the changes in the structure and makeup of the proteins, lipids and carbohydrates present in the cell wall. As (III) and As (V) exposed exhibited rougher surfaces 156.120 nm and 109.609 nm, respectively than the control (103.112 nm). Peak-to-peak height measurements were 940.66 nm for the control, 1246.833 nm and 703.125 nm for As (III) and As (V). These considerably significant changes support As remediation phenomena by bacterial isolate.