Screening and characterization of potential cadmium biosorbent Alcaligenes strain from industrial effluent

Cadmium (Cd) is a heavy metal that is easily accumulated in the living organisms in connection with anthropogenic activities which may result in serious health problems. In the present study, five potential cadmium tolerant bacterial strains were isolated from industrial effluent with heavy metal contamination and were screened for biosorption potential with their active growth in different media. After growth in shake flasks containing mineral salt media and tryptone soya broth, cell pellet of AS-5 removed by centrifugation sequestered almost 98% and 69% of cadmium (a.i. 25 mg/l Cd) respectively. Other strains accumulated variable amounts of Cd. 16S rRNA gene sequence of AS-5 and its homology analysis using BLAST reveals its phylogenetic relationship with family β-proteobacteriaceae and 98% homology with Alcaligenes sp., a facultative anaerobe.