有机碳源对铜绿假单胞菌还原Cr(Ⅵ)的影响

Effect of organic carbon source on chromate reduction by Pseudomonas aeruginosa

采用批式实验,研究了2种有机碳源苹果酸和葡萄糖对铜绿假单胞菌还原Cr(Ⅵ)效果的影响,并从pH、氧化还原电位和细胞生长量等方面对2种有机碳源的影响差异及其原因进行了分析、探讨。结果表明,葡萄糖和苹果酸均能促进菌株对Cr(Ⅵ)的还原,苹果酸的促进作用比葡萄糖更加显著,加入葡萄糖和苹果酸时Cr(Ⅵ)还原率分别提高了16.34%和25.72%。加入苹果酸时的细胞生长量明显高于加入葡萄糖时的细胞生长量。添加葡萄糖时还原过程中培养基pH值下降,氧化还原电位上升,而添加苹果酸其变化趋势相反。添加了葡萄糖的培养基代谢液(无菌体细胞)对Cr(Ⅵ)具有较好的还原作用,但添加了苹果酸的培养基代谢液(无菌体细胞)不能还原Cr(Ⅵ)。

Batch experiments were carried out to investigate the effect of two organic carbon sources,malate and glucose on Cr（Ⅵ） reduction by Pseudomonas aeruginosa.The pH,redox potential and cell growth during Cr（Ⅵ） reduction were measured to analyze the difference in the effect of these two organic carbon sources.The results demonstrated that both of malate and glucose promoted bacterial Cr（Ⅵ） reduction and malate was better than glucose.The reduction efficiency increased with supplementation of glucose and malate by 16.34% and 25.72%,respectively.The cell growth was obviously higher with addition of malate than addition of glucose.Addition of glucose resulted in the decrease of pH and increase of redox potential in culture medium,while the trend of pH and redox potential variation was opposite to that when malate was applied.Cr（Ⅵ） was reduced by liquid culture metabolite（LCM,without cells） when glucose was added in liquid medium,but Cr（Ⅵ） was not reduced by LCM（without cells） when malate was used.