Chromium(VI) detoxification potential of Cellulosimicrobium cellulans isolate AM-81 with partial characterization of chromium reductase

Environmental pollution is a major dilemma of industrialization caused by untreated disposal of industrial waste. These effluents include various toxic chemicals including heavy metals. One of the top pollutants that are... [ view full abstract ]

Environmental pollution is a major dilemma of industrialization caused by untreated disposal of industrial waste. These effluents include various toxic chemicals including heavy metals. One of the top pollutants that are released through industrial effluents is chromium with known mutagenic and carcinogenic effects on all life forms. The present study is aimed at the isolation and characterization of chromium resistant bacteria that may have the potential to remediate Cr-polluted environment. Industrial effluent was collected from Sialkot, an industrial city of Pakistan, and bacteria were isolated and selected on the basis of resistance against chromium(VI). Highest Resistance of 375mM of Chromium(VI) was exhibited by isolate AM-81. 16S rRNA gene sequencing revealed the identity of the bacterial isolate AM-81 as Cellulosimicrobium cellulans. Besides chromium resistance, this isolate was found to be resistant to multiple heavy metals and antibiotics. Chromium(VI) reduction by this isolate was determined both aerobically and anaerobically under variable nutritional requirements and non-growth conditions. Cell free extract was purified using French press, ultracentrifugation and various chromatographic columns. The size of chromate reductase of Cellulosimicrobium cellulans isolate AM-81 was detected through SDS-PAGE. The bacterial isolate with known reductase activity can be exploited for the removal of chromium(VI) from industrial effluents thus can act as one of the prospective applicants for bioremediation purposes.