Cai Yafan, Zheng Zehui, Wang Xiaofen
College of Agronomy and Biotechnology/Biomass Engineering Center, China Agricultural University, Beijing 100193, China; Department of Biochemical conversion, Deutsches Biomassforschungszentrum gemeinnütziges GmbH, Torgauer Straße116, 04347 Leipzig, Germany.
College of Agronomy and Biotechnology/Biomass Engineering Center, China Agricultural University, Beijing 100193, China.
J Hazard Mater. 2021 Feb 5;403:123938. doi: 10.1016/j.jhazmat.2020.123938. Epub 2020 Sep 14.
Anaerobic digestion (AD) is used to treat waste and produce bioenergy. However, toxicants, which originate from the substrate, can inhibit or damage the digestion process. Methanogenic archaea (MA), which are the executor in the methanogenesis stage, are more sensitive than bacteria to these toxicants. This review discusses the effects of substrate-driven toxicants, namely, antibiotics, HS and sulfate, heavy metals (HMs), long-chain fatty acids (LCFAs), and ammonia nitrogen, on the activity of MAs, methanogenic pathways, and the inter-genus succession of MAs. The adverse effects of these five toxicants on MA include effects on pH, damages to cell membranes, the prevention of protein synthesis, changes in hydrogen partial pressure, a reduction in the bioavailability of trace elements, and hindrance of mass transfer. These effects cause a reduction in MA activity and the succession of MAs and methanogenic pathways, which affect AD performance. Under the stress of these toxicants, succession occurs among HA (hydrogenotrophic methanogen), AA (acetoclastic methanogen), and MM (methylotrophic methanogen), especially HA gradually replaces AA as the dominant MA. Simultaneously, the dominant methanogenic pathway also changes from the aceticlastic pathway to other methanogenic pathways. A comprehensive understanding of the impact of toxicants on MA permits more specific targeting when developing strategies to mitigate or eliminate the effects of these toxicants.
厌氧消化（AD）用于处理废物并生产生物能源。然而，源自底物的有毒物质会抑制或破坏消化过程。产甲烷古菌（MA）是甲烷生成阶段的执行者，比细菌对这些有毒物质更敏感。本文综述了底物驱动的有毒物质，即抗生素、硫化氢和硫酸盐、重金属（HMs）、长链脂肪酸（LCFAs）和氨氮，对MA活性、产甲烷途径以及MA属间演替的影响。这五种有毒物质对MA的不利影响包括对pH值的影响、对细胞膜的损伤、对蛋白质合成的抑制、氢分压的变化、微量元素生物有效性的降低以及传质的阻碍。这些影响导致MA活性降低以及MA和产甲烷途径的演替，从而影响AD性能。在这些有毒物质的胁迫下，氢营养型产甲烷菌（HA）、乙酸营养型产甲烷菌（AA）和甲基营养型产甲烷菌（MM）之间会发生演替，尤其是HA逐渐取代AA成为优势MA。同时，主要的产甲烷途径也从乙酸裂解途径转变为其他产甲烷途径。全面了解有毒物质对MA的影响有助于在制定减轻或消除这些有毒物质影响的策略时更有针对性。
