10.1021/es100198v.s001
Yangjian Cheng
Yangjian
Cheng
Fenbo Yan
Fenbo
Yan
Feng Huang
Feng
Huang
Wangsheng Chu
Wangsheng
Chu
Danmei Pan
Danmei
Pan
Zhi Chen
Zhi
Chen
Jinsheng Zheng
Jinsheng
Zheng
Meijuan Yu
Meijuan
Yu
Zhang Lin
Zhang
Lin
Ziyu Wu
Ziyu
Wu
Bioremediation of Cr(VI) and Immobilization as Cr(III) by <i>Ochrobactrum anthropi</i>
American Chemical Society
2010
coordination
Ochrobactrum anthropi system
cell debris
Cr
2010-08-15 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Bioremediation_of_Cr_VI_and_Immobilization_as_Cr_III_by_i_Ochrobactrum_anthropi_i_/2742910
Bioremediation of Cr(VI) through reduction relies on the notion that the produced Cr(III) may be precipitated or efficiently immobilized. However, recent reports suggest that soluble organo-Cr(III) complexes are present in various chromate-reducing bacterial systems. This work was designed to explore the factors that affect the immobilization of Cr(III) in the <i>Ochrobactrum anthropi</i> system. X-ray absorption fine structure analysis on the cell debris clearly verified that coordination of Cr(III) occurs on the surfaces via the chelating coordination with carboxyl- and amido-functional groups. However, competitive coordination experiments of Cr(III) revealed that the small molecules such as amino acids and their derivatives or multicarboxyl compounds hold stronger coordination ability with Cr(III) than with cell debris. We speculate that it is the preferential coordination of Cr(III) to the soluble organic molecules in the bacterial culture medium that inhibits effective immobilization of Cr(III) on the cells. On the basis of this understanding, a strategy with two-step control of the medium was proposed, and this achieved successful immobilization of Cr(VI) as Cr(III) by <i>O. anthropi</i> and <i>Planococcus citreus</i> in 5−50 L pilot-scale experiments.