Li Zhaoxia, Cui Entian, Gu Naipeng, Ma Weixing, Guo Qingyuan, Li Xuan, Jin Jianxiang, Wang Qun, Ding Cheng
School of Marine and Biological Engineering, Yancheng Institute of Technology, Yancheng, Jiangsu, 224051, China.
Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, Yancheng Institute of Technology, Yancheng, Jiangsu, 224051, China.
Environ Res. 2024 Jun 15;251(Pt 2):118663. doi: 10.1016/j.envres.2024.118663. Epub 2024 Mar 8.
Although less toxic than hexavalent chromium, Cr (Ⅲ) species still pose a threat to human health. The Cr (Ⅵ) should be converted to Cr (0) instead of Cr (Ⅲ), which is still involved in biological detoxification filed. Herein, for the first time, it was found that Cr(Ⅵ) can be reduced into Cr(0) by Bacillus cereus FNXJ1-2-3, a way to completely harmless treatment of Cr(Ⅵ). The bacterial strain exhibited excellent performance in the reduction, sorption, and accumulation of Cr(Ⅵ) and Cr (Ⅲ). XPS etching characterization inferred that the transformation of Cr(Ⅵ) into Cr(0) followed a reduction pathway of Cr(Ⅵ)→Cr (Ⅲ)→metallic Cr(0), in which at least two secretory chromium reductases (E and E) worked. Under the optimum condition, the yield ratio of Cr(0)/Cr (Ⅲ) reached 33.90%. In addition, the interfacial interactions, ion channels, chromium reductases, and external electron donors also contributed to the Cr(Ⅵ)/Cr(0) transformation. Findings of this study indicate that Bacillus cereus FNXJ1-2-3 is a promising bioremediation agent for Cr(Ⅵ) pollution control.
虽然三价铬的毒性低于六价铬，但仍然对人类健康构成威胁。应该将六价铬转化为零价铬，而不是仍参与生物解毒领域的三价铬。在此，首次发现蜡样芽孢杆菌FNXJ1-2-3可将六价铬还原为零价铬，这是一种对六价铬进行完全无害化处理的方法。该菌株在六价铬和三价铬的还原、吸附及积累方面表现出优异性能。X射线光电子能谱蚀刻表征推断，六价铬向零价铬的转化遵循六价铬→三价铬→金属零价铬的还原途径，其中至少有两种分泌型铬还原酶（E和E）起作用。在最佳条件下，零价铬/三价铬的产率比达到33.90%。此外，界面相互作用、离子通道、铬还原酶和外部电子供体也有助于六价铬/零价铬的转化。本研究结果表明，蜡样芽孢杆菌FNXJ1-2-3是一种用于控制六价铬污染的有前景的生物修复剂。
