A green chemical approach for biotransformation of Cr(VI) to Cr(III), utilizing Fusarium sp. MMT1 and consequent structural alteration of cell morphology

Abstract

Chromium (Cr) resistant fungal strain capable of reducing toxic hexavalent chromium to non-toxic trivalent form was isolated from tannery effluent. The strain belonged to the genus Fusarium as concluded on the basis of sugar utilization and molecular profiling studies. The Translation Elongation Factor 1-α (TEF) gene sequence of the strain was identified with the accession number JX170375 in NCBI. The biotransformation of Cr(VI) to Cr(III) was optimized by the following physico-chemical parameters: incubation temperature: 25°C, incubation time: 72h and initial pH: 5.0. Chromium reduction efficiency of the strain was observed to be 100% in growth medium after 72h of incubation. Proteomic profiling indicated a number of proteins to be down regulated in the fungal cell on exposure to chromium. Atomic force, confocal laser scanning and scanning electron micrographs revealed enhanced surface roughness index (5.2±0.2nm to 11.53±0.3nm), significant swelling and formation of cage like structures on the cell surface induced by the presence of Cr in growth medium. Thus biotransformation of Cr(VI) in industrial waste achieved with the isolated Fusarium sp. MMT1 strain, utilizes a green technique which is immensely beneficial for bioremediation.