Desjardin V, Bayard R, Huck N, Manceau A, Gourdon R
LAEPSI, INSA de Lyon, Villeurbanne, France.
Waste Manag. 2002;22(2):195-200. doi: 10.1016/s0956-053x(01)00069-1.
The effect of microbial activity on the chemical state of chromium, in a contaminated soil located in the Rhĵne-Alpes region (France), has been investigated. This soil contained 4,700 mg kg(-1) Cr, with about 40% present in the soluble hexavalent form. Indigenous microbial activity was found to significantly reduce Cr(VI) to the less mobile form (III) when the soil was incubated at 30 degrees C in an aqueous medium containing glucose and nutrients. A Cr(VI)-reducing strain of Streptomyces thermocarboxydus was isolated from the contaminated soil. The strain was found to metabolize Cr(VI) in a similar manner as an exogenous inoculum of Pseudomonas fluorescens LB300, and to precipitate chromium as a Cr oxyhydroxide with a gammaCrOOH-like local structure. The Cr(VI)-reducing activity of S. thermocarboxydus was induced, or significantly accelerated, by the aggregation of bacterial cells or their adhesion to suspended solid particles, and was stimulated in pure culture by glycerol and chromate.
对法国罗纳-阿尔卑斯地区一处受污染土壤中微生物活性对铬化学形态的影响进行了研究。该土壤含铬量为4700毫克/千克，约40%以可溶六价态存在。当土壤在含有葡萄糖和养分的水介质中于30℃培养时，发现本地微生物活性能显著将六价铬还原为迁移性较低的形态（三价铬）。从受污染土壤中分离出一株嗜热羧基链霉菌的六价铬还原菌株。发现该菌株代谢六价铬的方式与荧光假单胞菌LB300的外源接种物类似，并沉淀出具有类γ - CrOOH局部结构的氢氧化铬。嗜热羧基链霉菌的六价铬还原活性因细菌细胞聚集或其附着于悬浮固体颗粒而被诱导或显著加速，且在纯培养中受甘油和铬酸盐刺激。
