Reduction of Hexavalent Chromium by Viable Cells of Chromium Resistant Bacteria Isolated from Chromite Mining Environment

Table 2

Effect of cell density on Cr(VI) reduction by viable cells of Arthrobacter sp. SUK 1201.

Incubation, hr	% Cr(VI) reduced
	Cell density (cells/mL)
	12	5.40 ± 1.2	14.1 ± 2.6	20.0 ± 1.0	41.2 ± 1.6	66.0 ± 1.4
24	19.0 ± 0.8	24.0 ± 1.6	30.0 ± 1.8	64.2 ± 2.6	76.0 ± 0.9
48	34.0 ± 2.2	48.1 ± 0.6	75.0 ± 1.0	100 ± 0.6	100 ± 0.4

(Cr(VI) reduction was carried out in V. B. broth containing 100 µM Cr(VI) and a cell density ranging from 10⁶–10¹⁰ cells/mL. Incubation: 48 h at 25°C under continuous shaking (120 rpm). Residual Cr(VI) was estimated by usual diphenylcarbazide method. Results represent mean of triplicate experiments ± standard error).