Fig. 3.

Cr⁶⁺ and Cd²⁺ removed by Alishewanella sp. WH16-1. Control stands for null LB medium. Strain WH16-1 was incubated until OD₆₀₀ reach 1.0, and then amended with K₂CrO₄ (1 mmol/L) and CdCl₂ (0.06 mmol/L), respectively. The cultures were removed at 12 h intervals. After centrifuging at 12,000 rpm for 2 min, the supernatant was used to determine the residual concentration of Cr⁶⁺ and Cd²⁺. The concentration of Cr⁶⁺ and Cd²⁺ were measured by the UV spectrophotometer (DU800, Beckman, CA, USA) with the colorimetric diphenylcarbazide (DPC) method [46] and the atomic absorption spectrometry AAS, respectively