Takeuchi T L, Suzuki I
Department of Microbiology, University of Manitoba, Winnipeg, Canada.
J Bacteriol. 1994 Feb;176(3):913-6. doi: 10.1128/jb.176.3.913-916.1994.
The oxidation of sulfite by Thiobacillus thiooxidans was studied at various pH values with changing concentrations of potassium sulfite. The optimal pH for sulfite oxidation by cells was a function of sulfite concentrations, rising with increasing substrate concentrations, while that by the cell extracts was unaffected. The sulfite oxidation by cells was inhibited at high sulfite concentrations, particularly at low pH values. The results from kinetic studies show that the fully protonated form of sulfite, sulfurous acid or sulfur dioxide, is the form which penetrates the cells for the oxidation.
在不同pH值下，研究了氧化硫硫杆菌对亚硫酸盐的氧化作用，同时改变亚硫酸钾的浓度。细胞氧化亚硫酸盐的最佳pH值是亚硫酸盐浓度的函数，随着底物浓度的增加而升高，而细胞提取物的最佳pH值则不受影响。在高亚硫酸盐浓度下，特别是在低pH值时，细胞对亚硫酸盐的氧化作用受到抑制。动力学研究结果表明，亚硫酸盐的完全质子化形式，即亚硫酸或二氧化硫，是穿透细胞进行氧化的形式。
