Metabolic changes of Acidithiobacillus caldus under Cu2+ stress

✍ Scribed by Lexian Xia; Chu Yin; Liyuan Cai; Guanzhou Qiu; Wenqing Qin; Bin Peng; Jianshe Liu

• Book ID: 102393728
• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 349 KB
• Volume: 50
• Category: Article
• ISSN: 0233-111X
• DOI: 10.1002/jobm.201000051

✦ Synopsis

Abstract

Metabolic changes were investigated by measuring the depletion of dissolved oxygen and the enzymatic activities of sulfur metabolism in Acidithiobacillus caldus (A. caldus) before and after copper stress. The results showed that high concentrations of Cu^2+^ have an indirect negative effect on the sulfite oxidase and the APS reductase involved in sulfur metabolism when A. caldus is cultured in medium with elemental sulfur as its growth energy. This leads to a decrease in the respiration rate and the growth rate. The changes of activity are negatively correlated with the intracellular Cu^2+^ concentration through an indirect interaction mechanism. A. caldus was able to induce an efflux of copper ions by forming an ATPase‐dependent pump, which transported copper ions by consuming ATP. The negative effect of Cu^2+^ on the bacterial metabolism could be minimized by the copper efflux when the bacteria were adapted in medium containing Cu^2+^ for a long time. However, this bacterial rejuvenation became weaker when grown in medium containing higher concentrations of copper ions. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)