EN
Initially 73 chromium(VI)-resisting bacteria were isolated from nine samples collected from three industrial cities (Kasur, Kalashahkaku, and Sialkot) of Pakistan. Eleven strains with the highest chromium resistance also were selected. Among these highly resistant selected isolates (MTC ≥ 250 mM), AM81 (Cellulosimicrobium cellulans) showed the highest MTC of 375 mM against Cr(VI). Biochemical characterization was used to identify the families of bacteria after initial screening. Four isolates shared origin with Staphylococcaceae — three each with Promicromonosporaceae and Microbacteriaceae, and a single strain was related to Bacillales Family XII incertaesedis. 16S rRNA was used for species identification and found KM2 to be Leucobacter chironomid, KS1W; Microbacterium sp., SIS21 and KSKE42; Staphylococcus saprophyticus, SIS22; Staphylococcus sciuri, SIS51; Staphylococcus xylosus, MWM81, AM81, and KSKE3; Cellulosimicrobium cellulans, MWM82; and Microbacterium paraoxydans, KSKE41 was Exiguobacterium profundum. Strains tolerated the stress of other heavy metals (cadmium, mercury, copper, zinc, arsenic, and manganese) to variable extant along with chromium(VI). Antibiotic susceptibility was found to be more for streptomycin (10 μg ml-1) and the least susceptibility was observed for kanamycin (30 μg ml-1).