Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, PR China; Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, PR China.
Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, PR China.
Sci Total Environ. 2024 Dec 1;954:176240. doi: 10.1016/j.scitotenv.2024.176240. Epub 2024 Sep 16.
Sulfide stress is a common inhibition factor in anaerobic digestion systems with sulfur-rich feedstocks. Quorum sensing (QS) signaling molecule N-acyl-homoserine lactones (AHLs) possess positive effect on promoting anaerobic digestion. However, the micro-biological mechanisms of AHLs affecting syntrophic metabolism and microbial self-adaptation have not yet been deciphered in anaerobic digestion under sulfide stress. In this study, the CH production increased by 21.34 % at 20 μM AHLs addition in anaerobic digestion under sulfide stress. AHLs contributed to establishing potential syntrophic relationship between acidifying bacteria (unclassified_o__Bacteroidales, Lentimicrobium, Acetoanaerobium, Longilinea, and Sphaerochaetaa) and Methanothrix. AHLs promoted syntrophic metabolism by boosting microbial metabolic activity and interspecies electron transfer (IET) process under sulfide stress. For microbial metabolic activity, AHLs promoted the key enzyme synthesis in acidogenesis and methanogenesis. For IET process, AHLs promoted the assembly and synthesis of conductive pili, and synthesis and secretion of riboflavin. Furthermore, AHLs promoted microbial self-adaptation including two component system, lipopolysaccharide biosynthesis, and DNA repair, which were important evidences that microbial resistance to sulfide stress was enhanced by AHLs. Microbial self-adaptation provided favorable foundation and safeguard for syntrophic metabolisms under sulfide stress. These findings deciphered the micro-biological mechanisms of AHLs enhancing anaerobic digestion under sulfide stress.
在富含硫的饲料厌氧消化系统中，硫化物胁迫是一种常见的抑制因素。群体感应（QS）信号分子 N-酰基高丝氨酸内酯（AHLs）对促进厌氧消化有积极作用。然而，在硫化物胁迫下的厌氧消化中，AHLs 影响共代谢和微生物自适应性的微生物学机制尚未被破译。在本研究中，在硫化物胁迫下的厌氧消化中，添加 20 μM AHLs 可使 CH4 产量增加 21.34%。AHLs 有助于在酸化菌（未分类_o__拟杆菌门、 Lentimicrobium、Acetoanaerobium、Longilinea 和 Sphaerochaetaa）和产甲烷菌之间建立潜在的共代谢关系。AHLs 通过在硫化物胁迫下提高微生物代谢活性和种间电子传递（IET）过程来促进共代谢。对于微生物代谢活性，AHLs 促进了产酸和产甲烷过程中的关键酶合成。对于 IET 过程，AHLs 促进了导电菌毛的组装和合成，以及核黄素的合成和分泌。此外，AHLs 促进了微生物的自适应性，包括双组分系统、脂多糖生物合成和 DNA 修复，这是微生物对硫化物胁迫的抗性增强的重要证据。微生物自适应性为硫化物胁迫下的共代谢提供了有利的基础和保障。这些发现揭示了 AHLs 增强硫化物胁迫下厌氧消化的微生物学机制。
