Discovery of a new genus of anaerobic ammonium oxidizing bacteria with a mechanism for oxygen tolerance
Discovery of a new genus of anaerobic ammonium oxidizing bacteria with a mechanism for oxygen tolerance
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DOI：
10.1016/j.watres.2022.119165
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发表时间：
2022-10-17
期刊：
影响因子：
12.8
通讯作者：
Gu，Ji-Dong
中科院分区：
文献类型：
--
作者：
Yang，Yuchun;Lu，Zhongyi;Gu，Ji-Dong
在过去的20年里，在理解厌氧氨氧化(Anammox)细菌的核心机制方面取得了很大进展，但关于它们的生存策略仍有几个讨论点。在这里，我们在废水处理生物膜系统中发现了一种新的厌氨氧化细菌属，暂定名为“CandidatusLoosdrechtia Aeroterans”。除了所有核心厌氧氨氧化代谢的基因外，它还编码和转录了参与异化硝酸盐还原为氨(DNRA)的基因，该基因与小分子有机酸的氧化作用相结合，可用于补充铵并维持其代谢。令人惊讶的是，它独特地含有一种新的铁氧还蛋白依赖的硝酸还原酶，这种酶在任何其他anammox基因组中都没有发现，可能会在硝酸盐同化过程中赋予它选择性优势。与许多其他微生物一样，与氧化应激抗性相关的超氧化物歧化酶和过氧化氢酶是由“Ca”编码和转录的。耐气性Loosdrechtia Aeroterans。有趣的是，胆红素氧化酶(BOD)可能与厌氧氨氧化细菌在氧气浓度波动下的耐氧性有关，它被发现存在于“Ca.Loosdrechtia Aerotolans”和FourCa中。Brocadia基因组，并用纯化的异源表达蛋白证明其活性。随后对厌氧氨氧化细菌中氧活性蛋白的调查揭示了其他以前未被检测到的氧气防御系统的存在。新型CBB3型细胞色素C氧化酶和双功能过氧化氢酶-过氧化氢酶可能对TOCA具有选择性优势。Kuenenia和CA.Scaldua面临氧气浓度的频繁变化。这个新属的发现极大地拓宽了我们对厌氧氨氧化细菌生态生理学的理解。此外，不同的厌氧氨氧化细菌所采用的不同的耐氧性策略促进了我们对其生态位适应性的了解，并为基于厌氧氨氧化的废水处理系统的运行提供了有价值的见解。
In the past 20 years, there has been a major stride in understanding the core mechanism of anaerobic ammonium-oxidizing (anammox) bacteria, but there are still several discussion points on their survival strategies. Here, we discovered a new genus of anammox bacteria in a full-scale wastewater-treating biofilm system, tentatively named “CandidatusLoosdrechtia aerotolerans”. Next to genes of all core anammox metabolisms, it encoded and transcribed genes involved in the dissimilatory nitrate reduction to ammonium (DNRA), which coupled to oxidation of small organic acids, could be used to replenish ammonium and sustain their metabolism. Surprisingly, it uniquely harbored a new ferredoxin-dependent nitrate reductase, which has not yet been found in any other anammox genome and might confer a selective advantage to it in nitrate assimilation. Similar to many other microorganisms, superoxide dismutase and catalase related to oxidative stress resistance were encoded and transcribed by “Ca. Loosdrechtia aerotolerans”. Interestingly, bilirubin oxidase (BOD), likely involved in oxygen resistance of anammox bacteria under fluctuating oxygen concentrations, was identified in “Ca.Loosdrechtia aerotolerans” and fourCa. Brocadia genomes, and its activity was demonstrated using purified heterologously expressed proteins. A following survey of oxygen-active proteins in anammox bacteria revealed the presence of other previously undetected oxygen defense systems. The novelcbb3-type cytochrome c oxidase and bifunctional catalase-peroxidase may confer a selective advantage toCa. Kuenenia andCa. Scalindua that face frequent changes in oxygen concentrations. The discovery of this new genus significantly broadens our understanding of the ecophysiology of anammox bacteria. Furthermore, the diverse oxygen tolerance strategies employed by distinct anammox bacteria advance our understanding of their niche adaptability and provide valuable insight for the operation of anammox-based wastewater treatment systems.