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 showe...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.展开更多
The reverse microemulsion system of Span 80-Tw ee n 80/liquid paraffin/acrylamide-H 2O was prepared, and the effects of n-b utanol,NaCl,Nc were studied with the conductivity method.The stability of re verse microemuls...The reverse microemulsion system of Span 80-Tw ee n 80/liquid paraffin/acrylamide-H 2O was prepared, and the effects of n-b utanol,NaCl,Nc were studied with the conductivity method.The stability of re verse microemulsion was reflected, and the information of its dynamic process wa s obtained by measuring its state changes continuously through testing its elect ronic conductivity by using electrochemistry.The results showed that the Span 80 -Tween 80/liquid paraffin/acrylamide-H 2O system was most stable when the HLB value approached 7.5, and its stability was enhanced when 5.0% (mass) NaCl or 10% (mass) Nc was added into this system.展开更多
基金Projects (50974140, 51274257) supported by the National Natural Science Foundation of ChinaProject (20090162110054) supported by the PhD Programs Foundation of Ministry of Education of China
文摘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.
文摘The reverse microemulsion system of Span 80-Tw ee n 80/liquid paraffin/acrylamide-H 2O was prepared, and the effects of n-b utanol,NaCl,Nc were studied with the conductivity method.The stability of re verse microemulsion was reflected, and the information of its dynamic process wa s obtained by measuring its state changes continuously through testing its elect ronic conductivity by using electrochemistry.The results showed that the Span 80 -Tween 80/liquid paraffin/acrylamide-H 2O system was most stable when the HLB value approached 7.5, and its stability was enhanced when 5.0% (mass) NaCl or 10% (mass) Nc was added into this system.
