ROLES FOR ENTERIC D-TYPE CYTOCHROME-OXIDASE IN N-2 FIXATION AND MICROAEROBIOSIS
ROLES FOR ENTERIC D-TYPE CYTOCHROME-OXIDASE IN N-2 FIXATION AND MICROAEROBIOSIS
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DOI：
10.1128/jb.172.4.2071-2078.1990
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发表时间：
1990-04-01
影响因子：
3.2
通讯作者：
ANTHONY, C
中科院分区：
文献类型：
--
作者：
HILL, S;VIOLLET, S;ANTHONY, C
缺乏d型细胞色素氧化酶(对O2具有高亲和力的末端氧化酶)的大肠杆菌菌株，在厌氧生长方面与野生株一样，从葡萄糖或甲酸盐中释放氢气的能力没有受到损害。携带肺炎克雷伯菌nif基因的接合子的厌氧合成和固氮酶活性也正常。然而，缺乏d型氧化酶的厌氧生长细菌对O2的行为与野生型不同：潜在吸氧量较低，发酵所支持的放氢和固氮酶活性受到O2更强的抑制，在没有可发酵碳源的情况下不发生依赖于O2的微氧固氮酶活性。这些结果表明，D型氧化酶在肠道细菌中具有两种功能，一是在微好氧条件下保存能量，二是保护厌氧过程不受O2的抑制。
Escherichia coli strains that lacked the d-type cytochrome oxidase, the terminal oxidase with a high affinity for O2, grew anaerobically as well as the wild type did and were not impaired in the ability to evolve H2 from either glucose or formate. The anaerobic synthesis and activity of nitrogenase in transconjugants of these strains carrying Klebsiella pneumoniae nif genes were also normal. However, the behavior towards O2 of anaerobically grown bacteria lacking the d-type oxidase differed from that of the wild type in the following ways: the potential O2 uptake was lower, H2 evolution and nitrogenase activity supported by fermentation were more strongly inhibited by O2, and microaerobic O2-dependent nitrogenase activity in the absence of a fermentable carbon source did not occur. These results show that the d-type oxidase serves two functions in enteric bacteria.sbd.to conserve energy under microaerobic conditions and to protect anaerobic processes from inhibition by O2.