COLD SHOCK OF BACTERIA:II. MAGNESIUM-MEDIATED RECOVERY FROM COLD SHOCK AND EXISTENCE OF TWO CRITICAL TEMPERATURE ZONES IN VARIOUS BACTERIA
COLD SHOCK OF BACTERIA:II. MAGNESIUM-MEDIATED RECOVERY FROM COLD SHOCK AND EXISTENCE OF TWO CRITICAL TEMPERATURE ZONES IN VARIOUS BACTERIA
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细菌的冷休克：II。
DOI：
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发表时间：
1969
期刊：
影响因子：
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通讯作者：
H. Takahashi
中科院分区：
文献类型：
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作者：
Mikio Sato;H. Takahashi
大肠杆菌，荧光假单胞菌，枯草芽孢杆菌细胞，收获在对数生长期，冷休克敏感的判断，他们的生活力的损失。在30 ℃下与合适的添加剂孵育后，冷休克细胞的活力迅速增加。在这些有效的药剂中，镁离子是最重要的，因为在不存在镁的情况下没有观察到活力的明显恢复。当寒冷袭击E。大肠杆菌细胞在30 ℃下用5 × 10 ~（-1）M醋酸镁孵育10 ~ 20 min，休克细胞的活力与未休克细胞的活力相当。添加2，4-二硝基苯酚到这样的系统抑制镁介导的恢复几乎完全。当进一步加入NAD或ATP+烟酰胺时，2，4-二硝基苯酚的抑制作用被解除。这一结果表明，NAD，可能作为一种能源，参与了恢复过程。冷休克E.在8-苯胺基-1-萘磺酸盐的帮助下证明了大肠杆菌细胞。加入反应混合物中的NAD或ATP对冷休克恢复的刺激作用可以通过这种渗透性增加来解释。用两种B都证实了冷冲击中存在两个临界温度区。subtilis和Ps.荧光菌当冷休克前细胞悬液的初始温度降低5°时，两个温度区均向较低温度移动约3-5°。
Escherichia coli, Pseudomonas fluorescens, and Bacillus subtilis cells, harvested at the logarithmic phase of growth, were susceptible to cold shock as judged by their loss in viabilities. Viabilities of cold shocked cells increased rapidly upon incubation at 30° with suitable additives. Among the effective agents, magnesium ion was the most important, because no appreciable recovery in viability was observed in the absence of magnesium. When the cold shocked E. coli cells were incubated at 30° with 5 X 10 M of magnesium acetate for 10 to 20 min, the viability of shocked cells became equal to that of unshocked cells. The addition of 2, 4-dinitrophenol to such systems inhibited the magnesium-mediated recovery almost completely. When NAD or ATP plus nicotinamide was further added to the reaction mixture, the inhibition by 2, 4-dinitrophenol was released. This result suggests that NAD, possibly as an energy source, is involved in the recovery process. An increase in permeability of cold shocked E. coli cells was demonstrated with the aid of 8-anilino-l-naphthalenesulfonate. The stimulatory effect of NAD or ATP added to the reaction mixture on the recovery from the cold shock could be explained by this permeability increase. The presence of two critical temperature zones in the cold shock was confirmed with both B. subtilis and Ps. fluorescens. When the initial temperature of the cell suspension before the cold shock was lowered by 5°, both temperature zones moved to lower temperatures approximately by 3-5°.