Takayama K, Armstrong E L, Davidson L A, Kunugi K A, Kilburn J O
Am Rev Respir Dis. 1978 Jul;118(1):113-7. doi: 10.1164/arrd.1978.118.1.113.
Cultures of Mycobacterium tuberculosis strain H37Ra were grownto early logarithmic phase at 37 degrees C and were incubated at 16 degrees, 20 degrees, and 25 degrees C. The decrease in this ability was more rapid at 20 degrees C than at 16 degrees C. Low-temperature incubation caused decreases in the ratios of mycolic acids and monounsaturated C16-19 fatty acids relative to the total of fatty acids synthesized. It also caused an increase in the ratio of saturated C24-26 fatty acids relative to the total of fatty acids synthesized. These ratios were based on the incorporation of radiolabel from 14C-acetate into fatty acids. These results showed that when M. tuberculosis H37Ra was incubated at low temperatures, it did not adapt by increasing the ratio of unsaturated to saturated fatty acids synthesized. The ability of the cells to synthesize mycolic acids was sharply decreased. These changes may lead to the loss of viability of M. tuberculosos H37Ra. Mycolic acid synthesis is similarly affected by exposure of cells to isoniazid, an antimycobacterial drug.
结核分枝杆菌H37Ra菌株的培养物在37℃培养至对数早期，然后分别在16℃、20℃和25℃孵育。在20℃时这种能力的下降比在16℃时更快。低温孵育导致相对于合成的脂肪酸总量，分枝菌酸和单不饱和C16 - 19脂肪酸的比例降低。它还导致相对于合成的脂肪酸总量，饱和C24 - 26脂肪酸的比例增加。这些比例是基于14C - 乙酸盐中的放射性标记掺入脂肪酸的情况。这些结果表明，当结核分枝杆菌H37Ra在低温下孵育时，它不会通过增加合成的不饱和脂肪酸与饱和脂肪酸的比例来适应。细胞合成分枝菌酸的能力急剧下降。这些变化可能导致结核分枝杆菌H37Ra的活力丧失。细胞暴露于抗结核药物异烟肼时，分枝菌酸的合成也受到类似影响。
