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

Table 1

Effect of Cr(VI) concentration on Cr(VI) reduction by Arthrobacter sp. SUK 1201.

Incubation, hr	% Cr(VI) reduced
	Concentration of Cr(VI), µM
	50	100	200	300	400	600	800
12	66.0 ± 0.7	46.0 ± 1.2	16.5 ± 2.6	28.0 ± 1.2	34.4 ± 1.9	35.8 ± 2.2	35.4 ± 1.9
24	100.0 ± 0.0	60.0 ± 2.1	32.3 ± 3.1	36.0 ± 1.6	50.0 ± 2.3	46.6 ± 2.1	45.0 ± 2.6
48	100.0 ± 0.0	100.0 ± 0.0	87.5 ± 1.5	73.3 ± 2.3	71.0 ± 3.5	70.0 ± 0.8	68.0 ± 2.5

(Cr(VI) reduction was carried out in V. B. broth containing 50–800 µM of Cr(VI). The initial cell density was maintained at 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).