PRECIPITATION OF CADMIUM BY CLOSTRIDIUM-THERMOACETICUM
PRECIPITATION OF CADMIUM BY CLOSTRIDIUM-THERMOACETICUM
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DOI：
10.1128/aem.59.1.7-14.1993
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发表时间：
1993-01-01
影响因子：
4.4
通讯作者：
LUNDIE, LL
中科院分区：
文献类型：
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作者：
CUNNINGHAM, DP;LUNDIE, LL
镉在1 mM的初始浓度完全沉淀的培养物的热醋酸梭菌在复杂的培养基。沉淀是能量依赖性的，需要半胱氨酸，虽然半胱氨酸本身并不作为生长底物。电子显微镜分析显示，在非饥饿细胞的表面，以及沉淀在周围介质中的局部区域的沉淀。添加镉对生长和产乙酸没有明显影响。然而，镍和镉在浓度（1 mM）下具有协同毒性，在该浓度下两者都没有毒性。从镉处理的文化中提取的蛋白质的量是在对照提取物的两倍高，总硫化物的量是在含镉的文化比在对照文化的四倍高。在镉处理的和对照培养物的提取物中观察到相当水平的半胱氨酸脱氢酶活性，但在镉处理的培养物中比在未处理的对照中最早表达酶活性约24小时。
Cadmium at an initial concentration of 1 mM was completely precipitated by cultures of Clostridium thermoaceticum in complex medium. The precipitation was energy dependent and required cysteine, although cysteine alone did not act as a growth substrate. Electron microscopic analysis revealed localized areas of precipitation at the surfaces of nonstarved cells as well as precipitate in the surrounding medium. The addition of cadmium had no apparent effect on growth or acetogenesis. However, nickel and cadmium were synergistically toxic at a concentration (1 mM) at which neither alone was toxic. The amount of protein extracted from cadmium-treated cultures was twofold higher than that in control extracts, and the amount of total sulfide was fourfold higher in cultures containing cadmium than in control cultures. Comparable levels of cysteine desulfhydrase activity were observed in extracts of both cadmium-treated and control cultures, but the enzyme activity was expressed maximally about 24 h earlier in the cadmium-treated cultures than in the untreated controls.