Formate simultaneously reduces oxidase activity and enhances respiration in Campylobacter jejuni
Formate simultaneously reduces oxidase activity and enhances respiration in Campylobacter jejuni
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DOI：
10.1038/srep40117
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发表时间：
2017-01-16
影响因子：
4.6
通讯作者：
Rajashekara, Gireesh
中科院分区：
文献类型：
--
作者：
Kassem, Issmat I.;Candelero-Rueda, Rosario A.;Rajashekara, Gireesh
食源性微需氧病原体空肠弯曲菌具有一个周质甲酸脱氢酶和两个末端氧化酶，分别用于代谢甲酸和促进氧作为末端电子受体的使用。甲酸盐是C.空肠，抑制其他细菌中的氧化酶活性。在这里，我们假设甲酸可能会影响能量代谢和微氧生存在C。空肠。随后，我们证明了C.与其它有机酸相比，空肠81-176（野生型）表现出增强的对甲酸的化学吸引和呼吸作用。甲酸也显著提高了C.空肠的生长，运动，和生物膜的形成微氧（5%O-2）条件下。然而，甲酸减少氧化酶活性在微氧条件下，以及耐氧性和生物膜形成在环境氧气条件下。编码核糖核苷酸还原酶（RNR）和蛋白质，促进使用替代电子受体的基因的表达普遍增加甲酸的存在下。综上所述，甲酸盐可能在优化C.空肠对宿主缺氧胃肠道的适应。通过影响氧化酶活性，甲酸可能促进电子穿梭到替代受体，同时可能保留有限的氧浓度用于其他基本功能，例如通过RNR进行DNA合成，这是C所需的。空肠生长。
The foodborne microaerophilic pathogen, Campylobacter jejuni, possesses a periplasmic formate dehydrogenase and two terminal oxidases, which serve to metabolize formate and facilitate the use of oxygen as a terminal electron acceptor, respectively. Formate, a primary energy source for C. jejuni, inhibits oxidase activity in other bacteria. Here, we hypothesized that formate might affect both energy metabolism and microaerobic survival in C. jejuni. Subsequently, we showed that C. jejuni 81-176 (wildtype) exhibited enhanced chemoattraction to and respiration of formate in comparison to other organic acids. Formate also significantly increased C. jejuni's growth, motility, and biofilm formation under microaerobic (5% O-2) conditions. However, formate reduced oxidase activity under microaerobic conditions as well as aerotolerance and biofilm formation under ambient oxygen conditions. The expression of genes encoding the ribonucleotide reductase (RNR) and proteins that facilitate the use of alternative electron acceptors generally increased in the presence of formate. Taken together, formate might play a role in optimizing C. jejuni's adaptation to the oxygen-limited gastrointestinal tract of the host. By affecting oxidase activity, formate possibly facilitates shuttling electrons to alternative acceptors, while likely conserving limited oxygen concentrations for other essential functions such as DNA synthesis via RNR which is required for C. jejuni's growth.