EFFECT OF OSMOTIC-PRESSURE OF GROWTH MEDIUM ON FABB MUTANTS OF ESCHERICHIA-COLI
EFFECT OF OSMOTIC-PRESSURE OF GROWTH MEDIUM ON FABB MUTANTS OF ESCHERICHIA-COLI
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DOI：
10.1128/jb.117.3.971-977.1974
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发表时间：
1974-01-01
影响因子：
3.2
通讯作者：
STEENBAKKERS, JF
中科院分区：
文献类型：
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作者：
BROEKMAN, JH;STEENBAKKERS, JF
大肠杆菌的温度敏感不饱和脂肪酸（fabB）营养缺陷型在不存在不饱和脂肪酸的高渗透压培养基中在限制温度下生长。如果突变培养物缺乏不饱和脂肪酸并在裂解开始前收获，则细胞的脂肪酸组成与在高渗透培养基中生长直至对数期晚期的细胞的脂肪酸组成相同。有证据表明，在高渗透介质中体内不饱和脂肪酸生物合成显着增加。该增加可能是由于温度敏感fabB 产品的部分激活所致。除了温度敏感的fabB产物的刺激之外，培养基的最小渗透压似乎对于含有具有改变的脂肪酸组成的脂质的细胞的生长是必要的。在不存在不饱和脂肪酸的情况下，fabA突变体不能在高渗透培养基中生长。在温度敏感的fabA突变体中没有检测到体内不饱和脂肪酸生物合成的增加。
Temperature-sensitive, unsaturated fatty acid (fabB) auxotrophs ofEscherichia colican grow at the restrictive temperature in the absence of unsaturated fatty acid in a medium with a high osmotic pressure. If a mutant culture was starved for unsaturated fatty acids and harvested just before the lysis started, the fatty acid composition of the cells was the same as that of cells grown until late log phase in a high-osmotic medium. Evidence is presented that the in vivo unsaturated fatty acid biosynthesis is significantly increased in a high osmotic medium. The increase is probably due to a partial activation of the temperature-sensitivefabBproduct. Besides the stimulation of the temperature-sensitivefabBproduct, a minimal osmotic pressure of the medium appeared to be necessary to allow growth of cells containing lipids with a changed fatty acid composition.fabAmutants are unable to grow in a high-osmotic medium in the absence of unsaturated fatty acids. No increase in the in vivo unsaturated fatty acid biosynthesis could be detected in the temperature-sensitivefabAmutants.