School of Resources and Environmental Engineering, Anhui University, Hefei, 230601, China.
Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Science, Chongqing, 400714, China.
Microb Ecol. 2023 Jul;86(1):311-324. doi: 10.1007/s00248-022-02056-y. Epub 2022 Jun 16.
Landfills are a unique "terrestrial ecosystem" and serve as a significant carbon sink. Microorganisms convert biodegradable substances in municipal solid waste (MSW) to CH, CO, and microbial biomass, consisting of the carbon cycling in landfills. Microbial-mediated N and S cycles are also the important biogeochemical process during MSW decomposition, resulting in NO and HS emission, respectively. Meanwhile, microbial-mediated N and S cycles affect carbon cycling. How microbial community structure and function respond to C, N, and S cycling during solid waste decomposition, however, are not well-characterized. Here, we show the response of bacterial and archaeal community structure and functions to C, N, and S cycling during solid waste decomposition in a long-term (265 days) operation laboratory-scale bioreactor through 16S rRNA-based pyrosequencing and metagenomics analysis. Bacterial and archaeal community composition varied during solid waste decomposition. Aerobic respiration was the main pathway for CO emission, while anaerobic C fixation was the main pathway in carbon fixation. Methanogenesis and denitrification increased during solid waste decomposition, suggesting increasing CH and NO emission. In contract, fermentation decreased along solid waste decomposition. Interestingly, Clostridiales were abundant and showed potential for several pathways in C, N, and S cycling. Archaea were involved in many pathways of C and N cycles. There is a shift between bacteria and archaea involvement in N fixation along solid waste decomposition that bacteria Clostridiales and Bacteroidales were initially dominant and then Methanosarcinales increased and became dominant in methanogenic phase. These results provide extensive microbial mediation of C, N, and S cycling profiles during solid waste decomposition.
垃圾填埋场是一种独特的“陆地生态系统”，是一个重要的碳汇。微生物将城市固体废物（MSW）中的可生物降解物质转化为 CH、CO 和微生物生物量，构成了垃圾填埋场中的碳循环。微生物介导的氮和硫循环也是 MSW 分解过程中的重要生物地球化学过程，分别导致 NO 和 HS 的排放。同时，微生物介导的氮和硫循环会影响碳循环。然而，微生物群落结构和功能如何响应固体废物分解过程中的 C、N 和 S 循环尚不清楚。在这里，我们通过 16S rRNA 焦磷酸测序和宏基因组学分析，展示了细菌和古菌群落结构和功能对长期（265 天）运行实验室规模生物反应器中固体废物分解过程中 C、N 和 S 循环的响应。在固体废物分解过程中，细菌和古菌群落组成发生了变化。好氧呼吸是 CO 排放的主要途径，而厌氧 C 固定是碳固定的主要途径。随着固体废物分解，甲烷生成和反硝化作用增加，表明 CH 和 NO 的排放增加。相反，发酵随着固体废物的分解而减少。有趣的是，梭菌目在 C、N 和 S 循环的几个途径中丰富，并表现出潜在的能力。古菌参与了 C 和 N 循环的许多途径。随着固体废物分解，固氮过程中细菌和古菌的参与发生了转变，最初是细菌梭菌目和拟杆菌目占主导地位，然后甲烷杆菌目增加并在产甲烷阶段占主导地位。这些结果提供了固体废物分解过程中广泛的微生物介导的 C、N 和 S 循环特征。
