FERMENTATIVE METABOLISM OF PYRUVATE BY RHODOSPIRILLUM-RUBRUM AFTER ANAEROBIC GROWTH IN DARKNESS
FERMENTATIVE METABOLISM OF PYRUVATE BY RHODOSPIRILLUM-RUBRUM AFTER ANAEROBIC GROWTH IN DARKNESS
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DOI：
10.1128/jb.131.2.533-543.1977
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发表时间：
1977-01-01
影响因子：
3.2
通讯作者：
UFFEN, RL
中科院分区：
文献类型：
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作者：
GORRELL, TE;UFFEN, RL
R.红色酵母在黑暗中厌氧生长，并通过丙酮酸甲酸裂解酶反应发酵丙酮酸钠。在用丙酮酸钠厌氧黑暗或光照孵育30分钟期间，在pH 8.3下进行的反应中，来自发酵培养细胞的粗提取物产生约6 μ mol乙酰磷酸和甲酸/mg蛋白质。细胞提取物在7.3-7.5的表观pH最佳值下也催化[14 C]甲酸钠交换成丙酮酸钠，但在该较低pH值下仅产生约2.5 μ mol乙酰磷酸。R.红色也可能形成丙酮酸盐：铁氧还蛋白氧化还原酶活性，如低碳酸氢盐交换活性所证明，但其在厌氧暗生长细胞中参与丙酮酸盐代谢尚不清楚。在厌氧，黑暗生长与丙酮酸，甲酸是一个中间体在H2和CO2气体的演变。与光合生长细胞中依赖光的H2-固氮酶系统产生H2不同，发酵R.红色通过不受光影响的CO敏感的甲酸氢解酶反应发生。
R. rubrum grew anaerobically in darkness and fermented sodium pyruvate by a pyruvate formate-lyase reaction. During 30 min of anaerobic dark or light incubation with sodium pyruvate, crude extracts from fermentatively grown cells produced about 6 .mu.mol of acetylphosphate and formate/mg of protein in reactions performed at pH 8.3. Cell extracts also catalyzed the exchange of sodium [14C]formate into sodium pyruvate at an apparent pH optimum of 7.3-7.5, but only about 2.5 .mu.mol of acetylphosphate was produced at this lower pH value. R. rubrum may also form pyruvate:ferredoxin oxidoreductase activity, as evidenced by low bicarbonate exchange activity, but its participation in pyruvate metabolism in anaerobic dark-grown cells was not understood. During anaerobic, dark growth with pyruvate, formate was an intermediate in H2 and CO2 gas evolution. Unlike H2 production by a light-dependent H2-nitrogenase system in photosynthetically grown cells, H2 formation in fermenting R. rubrum occurred through a CO-sensitive formic hydrogenlyase reaction not influenced by light.