Integrated Metagenomic and Metaproteomic Analyses Unravel Ammonia Toxicity to Active Methanogens and Syntrophs, Enzyme Synthesis, and Key Enzymes in Anaerobic Digestion.
Integrated Metagenomic and Metaproteomic Analyses Unravel Ammonia Toxicity to Active Methanogens and Syntrophs, Enzyme Synthesis, and Key Enzymes in Anaerobic Digestion.
复制标题
DOI：
10.1021/acs.est.1c00797
复制
发表时间：
2021-10
影响因子：
11.4
通讯作者：
Chao Liu;Haining Huang;Xu Duan;Yinguang Chen
中科院分区：
文献类型：
--
作者：
Chao Liu;Haining Huang;Xu Duan;Yinguang Chen
在厌氧消化过程中，活性微生物组通过转录和翻译合成酶，然后酶催化底物的多步生物转化，然后产生甲烷。然而，关于氨如何影响含有表达的酶、酶合成和关键酶的真正活性的微生物的信息很少。在这项研究中，综合宏基因组学和元蛋白质组学的研究表明，氨不仅抑制专性乙酸营养型产甲烷菌，而且还抑制互养型丙酸和丁酸氧化类群及其辅助细菌（脱硫弧菌属），从而降低丙酸和丁酸→乙酸→甲烷的生物转化。氨对水解酸化菌的总数量没有影响，但对氨有抗性的细菌有所增加。我们的研究还表明，氨通过抑制转录过程中的RNA聚合酶（亚基A'和D）以及翻译过程中的核糖体（大（L3，L12，L13，L22和L25）和小（S3，S3 Ae和S7）核糖体亚基）和氨酰-tRNA合成（氨酰-tRNA合成酶）来抑制酶的合成过程。进一步的研究表明，甲基丙二酰辅酶A β，乙酰辅酶A C-乙酰基转移酶，和CH 3-CoM还原酶，调节丙酸和丁酸氧化和acetoclastic甲烷化，显着下调氨。这项研究为氨如何抑制厌氧消化的基本机制提供了内在的见解。
During anaerobic digestion, the active microbiome synthesizes enzymes by transcription and translation, and then enzymes catalyze multistep bioconversions of substrates before methane being produced. However, little information is available on how ammonia affects truly active microbes containing the expressed enzymes, enzyme synthesis, and key enzymes. In this study, an integrated metagenomic and metaproteomic investigation showed that ammonia suppressed not only the obligate acetotrophic methanogens but also the syntrophic propionate and butyrate oxidation taxa and their assistant bacteria (genus Desulfovibrio), which declined the biotransformations of propionate and butyrate → acetate → methane. Although the total population of the hydrolyzing and acidifying bacteria was not affected by ammonia, the bacteria with ammonia resistance increased. Our study also revealed that ammonia restrained the enzyme synthesis process by inhibiting the RNA polymerase (subunits A' and D) during transcription and the ribosome (large (L3, L12, L13, L22, and L25) and small (S3, S3Ae, and S7) ribosomal subunits) and aminoacyl-tRNA synthesis (aspartate-tRNA synthetase) in translation. Further investigation suggested that methylmalonyl-CoA mutase, acetyl-CoA C-acetyltransferase, and CH3-CoM reductase, which regulate propionate and butyrate oxidation and acetoclastic methanation, were significantly downregulated by ammonia. This study provides intrinsic insights into the fundamental mechanisms of how ammonia inhibits anaerobic digestion.