Bioaccumulation of Heavy Metals by Metal-Resistant Bacteria Isolated from Tagetes minuta Rhizosphere, Growing in Soil Adjoining Automobile Workshops

The present study deals with isolation, identification and characterization of some indigenous heavy metal resistant bacteria isolated from rhizosphere of Tagetes minuta, growing in soil adjoining automobile workshops to investigate their bioaccumulation capacity for three selected metals Cr(VI), Ni(II) and Cd(II). The plant was selected due to its natural abundance in the climate of Kashmir and also in the area of study. On the basis of morphological, biochemical, 16S rRNA gene sequencing, the isolates were identified as B. cereus BDBC01, B. cereus AVP12 and B. cereus NC7401. At maximum studied concentration of metal ions (250 mgl(-1)), in above sequence, the strains accumulated 118.2, 121.87 and 90 mg/g Cr (VI), 135, 127.5 and 146.25 mg/g Ni (II) and 120, 129.37, 135 mg/g Cd(II). Langmuir and Freundlich models were applied and found suitable to describe biosorption of selected metals by the isolated strains.