Gouesbet G, Abaibou H, Wu L F, Mandrand-Berthelot M A, Blanco C
Département Membranes et Osmorégulation, Université de Rennes I, France.
J Bacteriol. 1993 Jan;175(1):214-21. doi: 10.1128/jb.175.1.214-221.1993.
The influence of the osmolarity of the growth medium on anaerobic fermentation and nitrate respiratory pathways was analyzed. The levels of several enzymes, including formate dehydrogenase, hydrogenase, and nitrate reductase, plus a nickel uptake system were examined, as was the expression of the corresponding structural and regulatory genes. While some functions appear to be only moderately affected by an increase in osmolarity, others were found to vary considerably. An increase in the osmolarity of the medium inhibits both fermentation and anaerobic respiratory pathways, though in a more dramatic fashion for the former. fnr expression is affected by osmolarity, but the repression of anaerobic gene expression was shown to be independent of FNR regulatory protein, at least for hyd-17 and fdhF. This repression could be mediated by the intracellular concentration of potassium and is reversed by glycine betaine.
分析了生长培养基的渗透压对厌氧发酵和硝酸盐呼吸途径的影响。检测了包括甲酸脱氢酶、氢化酶和硝酸盐还原酶在内的几种酶的水平，以及镍摄取系统，同时也检测了相应结构基因和调控基因的表达。虽然有些功能似乎仅受到渗透压升高的适度影响，但其他功能则有很大差异。培养基渗透压的升高会抑制发酵和厌氧呼吸途径，不过对前者的抑制作用更为显著。fnr的表达受渗透压影响，但厌氧基因表达的抑制至少对于hyd-17和fdhF而言，显示出与FNR调控蛋白无关。这种抑制可能由细胞内钾离子浓度介导，并可被甘氨酸甜菜碱逆转。
