Wang Gaojun, Fu Peng, Zhang Bo, Zhang Ji, Huang Qiuyi, Yao Gaofei, Li Qian, Dzakpasu Mawuli, Zhang Jianfeng, Li Yu-You, Chen Rong
Key Lab of Environmental Engineering (Shaanxi Province), School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an 710055, PR China; International S&T Cooperation Center for Urban Alternative Water Resources Development, Key Laboratory of Northwest Water Resource, Environment and Ecology (Ministry of Education), Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an 710055, PR China.
Key Lab of Environmental Engineering (Shaanxi Province), School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an 710055, PR China.
Bioresour Technol. 2023 Nov;388:129773. doi: 10.1016/j.biortech.2023.129773. Epub 2023 Sep 16.
This study explored the mechanisms by which biochar mitigates ammonia inhibition in anaerobic digestion (AD) of swine manure. Findings show 2-8 g/L exogenous ammonia dosages gradually inhibited AD, leading to decreases in the efficiencies of hydrolysis, acidogenesis and methanogenesis by 3.4-70.8%, 6.0-82.0%, and 4.9-93.8%, respectively. However, biochar addition mitigated this inhibition and facilitated methane production. Biochar enhanced microbial activities related to electron transport and extracellular electron transfer. Moreover, biochar primarily enriched Methanosarcina, which, consequently, upregulated the genes encoding formylmethanofuran dehydrogenase and methenyltetrahydromethanopterin cyclohydrolase for the CO-reducing methanogenesis pathway by 26.9-40.8%. It is believed that biochar mediated direct interspecies electron transfer between syntrophic partners, thereby enhancing methane production under ammonia stress. Interestingly, biochar removal did not significantly impact the AD performance of the acclimated microbial community. This indicated the pivotal role of biochar in triggering methanogen evolution to mitigate ammonia stress rather than the indispensable function after the enrichment of ammonia-resistance methanogen.
本研究探讨了生物炭减轻猪粪厌氧消化（AD）中氨抑制作用的机制。研究结果表明，2-8 g/L的外源氨剂量会逐渐抑制厌氧消化，导致水解、产酸和产甲烷效率分别下降3.4-70.8%、6.0-82.0%和4.9-93.8%。然而，添加生物炭可减轻这种抑制作用并促进甲烷生成。生物炭增强了与电子传递和细胞外电子转移相关的微生物活性。此外，生物炭主要富集了甲烷八叠球菌，因此，通过CO还原产甲烷途径编码甲酰甲烷呋喃脱氢酶和亚甲基四氢甲蝶呤环水解酶的基因上调了26.9-40.8%。据信，生物炭介导了互营伙伴之间的直接种间电子转移，从而在氨胁迫下提高了甲烷产量。有趣的是，去除生物炭对适应后的微生物群落的厌氧消化性能没有显著影响。这表明生物炭在触发产甲烷菌进化以减轻氨胁迫方面具有关键作用，而不是在富集耐氨产甲烷菌后具有不可或缺的功能。
