表面活性剂Tween-80对Acidithiobacillus ferrooxidans硫氧化和硫代谢相关蛋白质基因表达的影响

摘要

研究了表面活性剂Tween-80对Acidithiobacillus ferrooxidans ATCC 23270生长、硫氧化和硫代谢相关典型基因表达的影响.结果表明,当培养基中含有10-2 g/L Tween-80时,A.ferrooxidans的生长以及其对不溶性底物(S0和CuFeS2)的代谢得到了促进.在该条件下,经过24 d的生物浸出,黄铜矿的铜离子浸出率比对照组(不含Tween-80)高16％.FT-IR光谱分析表明,这可能是由于Tween-80的存在而导致胞外多聚物成分发生变化而引起的.用RT-qPCR来分析17个硫代谢相关基因在Tween-80存在时的表达差异.胞外蛋白质基因表达下调表明了Tween-80对细菌一硫吸附作用的影响.硫代谢相关酶基因表达水平的变化为硫代谢的研究提供了参考.%The effects of surfactant Tween-80 on the growth,sulfur oxidation,and expression of selected typical sulfur metabolism relevant genes of Acidithiobacillus ferrooxidans ATCC 23270 were investigated.The results showed that in the presence of 10-2 g/L Tween-80,the growth of A.ferrooxidans and its metabolism on the insoluble substrate S0 and CuFeS2 were promoted.After 24 d of bioleaching,the copper extraction yield of chalcopyrite at 10-2 g/L Tween-80 increased by 16％ compared with the bioleaching experiment without Tween-80.FT-IR spectra analysis revealed that the result was probably caused by the extracellular polymeric substances whose composition could be changed by the surfactant addition.RT-qPCR was used to analyze the differential expressions of 17 selected sulfur metabolism relevant genes in response to the addition of Tween-80.Down-regulation of the extracellular protein genes indicated the influence of Tween-80 on bacteria-sulfur adsorption.Variation of the expression level of the enzymes provided a supplement to sulfur metabolism investigation.