Cypionka H
Fakultät für Biologie, Universität Konstanz, Federal Republic of Germany.
Arch Microbiol. 1989;152(3):237-43. doi: 10.1007/BF00409657.
Uptake of 35S-labelled sulfate was studied with a new isolate of Desulfovibrio desulfuricans, strain CSN. Micromolar additions of sulfate (1-10 microM or nmol/mg protein) to cell suspensions incubated in 150 mM KCl at -1 degrees C were almost completely taken up and accumulated about 5,000-fold. Accumulation was not influenced by incubation in NaCl instead of KCl, by acidic pH (5.5) or by incubation under air for 10 min. In alkaline milieu (pH 8.5), after prolonged contact with air (2 h), or after growth with excess sulfate or thiosulfate as electron acceptor, the amount taken up was diminished approximately by half. Pasteurization inhibited sulfate uptake completely. With increasing concentrations of added sulfate (0.1 to 2.5 mM) the intracellular concentration increased only slowly up to 25 mM, and the accumulation factor decreased down to 8. Sulfate transport was reversible. Accumulated sulfate was rapidly lost from the cells after addition of excess non-labelled sulfate or after addition of the uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP). The ATPase inhibitor dicyclohexylcarbodiimide (DCCD) specifically inhibited sulfate reduction but had no immediate influence on sulfate accumulation. Addition of the phosphate analogue arsenate (5 mM) was without effect. These results were not in favour of an ATP-dependent transport system. The K+-H+-antiporter nigericin (in 150 mM KCl) and the Na+-H+-antiporter monensin (in 150 mM NaCl) caused partial inhibition of sulfate accumulation, whereas the K+-transporter valinomycin (in 150 mM KCl) and the Na+-H+ exchange inhibitor amiloride (2 mM) were without effect.(ABSTRACT TRUNCATED AT 250 WORDS)
利用脱硫脱硫弧菌新分离株CSN研究了35S标记硫酸盐的摄取情况。在-1℃下于150 mM KCl中孵育的细胞悬液中添加微摩尔浓度的硫酸盐（1-10 microM或nmol/mg蛋白质），几乎被完全摄取并积累了约5000倍。用NaCl代替KCl孵育、酸性pH值（5.5）或在空气中孵育10分钟对积累没有影响。在碱性环境（pH 8.5）中、与空气长时间接触（2小时）后，或在以过量硫酸盐或硫代硫酸盐作为电子受体生长后，摄取量大约减少一半。巴氏消毒法完全抑制硫酸盐摄取。随着添加硫酸盐浓度的增加（0.1至2.5 mM），细胞内浓度仅缓慢增加至25 mM，积累因子降至8。硫酸盐转运是可逆的。添加过量未标记硫酸盐或解偶联剂羰基氰化物间氯苯腙（CCCP）后，积累的硫酸盐会迅速从细胞中流失。ATP酶抑制剂二环己基碳二亚胺（DCCD）特异性抑制硫酸盐还原，但对硫酸盐积累没有立即影响。添加磷酸盐类似物砷酸盐（5 mM）没有效果。这些结果不支持ATP依赖的转运系统。K+-H+反向转运体尼日利亚菌素（在150 mM KCl中）和Na+-H+反向转运体莫能菌素（在150 mM NaCl中）会部分抑制硫酸盐积累，而K+转运体缬氨霉素（在150 mM KCl中）和Na+-H+交换抑制剂阿米洛利（2 mM）没有效果。（摘要截短至250字）
