铁载体在假交替单胞菌Cd^(2+)去除中的作用

Role of siderophore produced by Pseudoaltermonas sp. SCSE709-6 in the removal of Cd^(2+)

为探索铁载体在微生物重金属去除过程中的作用,利用一株高效除镉菌——假交替单胞菌Pseudoaltermonas species.SCSE709-6(P.sp.SCSE709-6),研究镉(Cd^(2+))的添加对铁载体产量的影响以及铁载体的添加对菌体去除Cd^(2+)的影响。结果表明:菌体代谢能够产生羟基羧酸盐型铁载体,其产量与细菌生物量相关。在Cd^(2+)浓度为0~0.4 mmol/L时铁载体量呈先增后减的变化趋势,当为0.2 mmol/L时铁载体量最大。当向含镉培养液中加入铁载体时,细菌的适应期缩短,说明铁载体能够与Cd^(2+)络合,从而降低镉的生物毒性,提高细菌对镉的去除效率。研究结果为P.sp.SCSE709-6高效除镉提供了一种科学解释,在微生物修复重金属镉污染中具有潜在的实际应用价值。

In order to explore the role of siderophore in the process of removal of heavy metals,Pseudoaltermonas sp. SCSE709-6（ P. sp. SCSE709-6）,was selected as a representative bacterium. The effect of Cd^2＋addition on siderophore production by P. sp.SCSE709-6 and the effect of siderophore addition on the removal of Cd^2＋were studied,respectively. Upon O-CAS assay,P. sp.SCSE709-6 showed a vivid positive result for siderophore production. Assays based on chemical properties indicated that siderophore produced by P. sp. SCSE709-6 was carboxylate type. The siderophore yield was correlated with the biomass. Siderophore production was increased first and then decreased when the Cd^2＋concentration was 0 - 0. 4 mmol/L,notable this value reached maximum at0. 2 mmol/L. It accelerated the adaptation of P. sp. SCSE709-6 to Cd^2＋while siderophore was added to the culture medium,as siderophore could be combined with Cd^2＋to reduce the toxicity of cadmium,leading to high removal efficiency of Cd^2＋. The results provided a scientific explanation of why P. sp. SCSE709-6 is highly efficient in removal of cadmium and P. sp. SCSE709-6 could be recommended as a potential candidate for application in bioremediation of heavy metals.