Kučera Igor, Sedláček Vojtěch
Department of Biochemistry, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic.
Microorganisms. 2020 Aug 12;8(8):1230. doi: 10.3390/microorganisms8081230.
has a branched electron transport chain with three terminal oxidases transferring electrons to molecular oxygen, namely -type and -type cytochrome oxidases and -type ubiquinol oxidase. In the present study, we focused on strains expressing only one of these enzymes. The competition experiments showed that possession of -type oxidase confers significant fitness advantage during oxygen-limited growth and supports the biofilm lifestyle. The -type oxidase was shown to allow rapid aerobic growth at a high oxygen supply. Activity of the denitrification pathway that had been expressed in cells grown anaerobically with nitrate was fully inhibitable by oxygen only in wild-type and strains, while in strains and dinitrogen production from nitrate and oxygen consumption occurred simultaneously. Together, the results highlight the importance of the -type oxidase for the denitrification phenotype and suggest a way of obtaining novel bacterial strains capable of aerobic denitrification.
具有一条分支的电子传递链，带有三种将电子传递给分子氧的末端氧化酶，即 - 型和 - 型细胞色素氧化酶以及 - 型泛醇氧化酶。在本研究中，我们聚焦于仅表达这些酶之一的菌株。竞争实验表明，拥有 - 型氧化酶在氧气受限生长期间赋予显著的适应性优势，并支持生物膜生活方式。 - 型氧化酶被证明能在高氧供应下实现快速有氧生长。仅在野生型和 菌株中，在以硝酸盐厌氧生长的细胞中表达的反硝化途径的活性仅被氧气完全抑制，而在 菌株和 菌株中，硝酸盐产生二氮和氧气消耗同时发生。总之，这些结果突出了 - 型氧化酶对反硝化表型的重要性，并提出了一种获得能够进行有氧反硝化的新型细菌菌株的方法。
