一株假单胞菌(Pseudomonas alcaliphila MBR)好氧还原亚硒酸钠为红色单质硒

Reduction of selenite to elemental red selenium under aerobic condition by Pseudomonas alcaliphila MBR

【目的】本实验室保藏的一株异化硝酸盐还原菌(Pseudomonas alcaliphila MBR),其能够在好氧环境下以有机碳源为电子供体,把易溶解、高毒性亚硒酸钠还原成为红色单质硒,本文对该菌株还原亚硒酸盐的特征进行了研究。【结果】结果表明该菌株可以在pH为6-11环境中生长,对亚硒酸钠有较强抗性,其MIC(minimal inhibitory concentration)可高达50 mmol/L。在5天时间内,菌体以柠檬酸钠为电子供体,把2 mmol/L亚硒酸钠完全还原为红色单质硒并主要积累于胞外。硝酸盐和还原型谷胱甘肽对菌体还原亚硒酸钠具有促进作用,初步确定菌体对亚硒酸钠的还原是细胞膜或细胞质中的某些物质催化的结果。【结论】本项研究为应用Pseudomonas alcaliphila MBR于生物反应器提供了重要基础。

[ Objeetive] We studied the reduction of soluble and highly toxic selenite to elemental red selenium, under aerobic condition by Pseudomonas alcaliphila MBR, with organic carbon as electron donor. [ Results] The strain could grow under pH 6-11 and resist to high concentration of selenite with the minimal inhibitory concentration of 50 mmol/L. After 5 days, the strain used sodium citrate as electron donor, and reduced 2.0 mmol/L selenite to elemental red selenium from the culture fluid, the elemental red selenium was stored outside the cells. The glutathione and nitrate could increase the number of reduction rate. [ Conclusion ] This study implies the application of Pseudornonas alcaliphila MBR to convert selenite to elemental red selenium.