| 低温产甲烷菌群对玉米秸秆低温厌氧消化的生物强化作用 |
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| 引用本文： | 张新杰,孙永明,闫淼,李金平,李颖.低温产甲烷菌群对玉米秸秆低温厌氧消化的生物强化作用[J].农业工程学报,2023,39(6):186-193. |
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| 作者姓名： | 张新杰 孙永明 闫淼 李金平 李颖 |
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| 作者单位： | 1. 兰州理工大学能源与动力工程学院，兰州 730050；2. 中国科学院广州能源研究所，广州 510640；3. 中国科学院可再生能源重点实验室，广州 510640；4. 甘肃省生物质能与太阳能互补供能系统重点实验室，兰州 730050;1. 兰州理工大学能源与动力工程学院，兰州 730050；4. 甘肃省生物质能与太阳能互补供能系统重点实验室，兰州 730050 |
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| 基金项目： | 中国科学院战略性先导科技专项(XDA21050400)；国家自然科学基金-面上项目（52170143）；广东省自然科学基金-面上项目 (2021A1515012082)；中国科学院青年创新促进会 |
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| 摘 要： | 为研究产甲烷菌群对秸秆低温厌氧消化的生物强化作用，试研究将长期驯化的低温产甲烷菌群投加至秸秆厌氧消化体系中，对比不同添加剂量(3%、6%、9%、12%、15%和18%)对低温(20℃)批式厌氧消化性能的影响。对产甲烷性能、中间代谢产物进行统计学和动力学分析，评价生物强化效果，确定最佳剂量，结合微生物群落分析揭示生物强化作用机制，结果表明：生物强化可促进秸秆低温厌氧消化，提高甲烷率1.27～2.24倍，促进乙酸和丙酸的降解，避免酸抑制，相比对照组缩短厌氧消化时间(T80)12～19d；动力学分析表明：生物强化可缩短厌氧消化的延滞期；统计学分析表明：强化甲烷产量的最佳剂量为12%，单位质量菌群强化甲烷产量的最佳剂量为6%；微生物群落分析显示生物强化促进低温厌氧消化的主要原因是提高了产甲烷菌Methanothrix和Methanosarcina相对丰度。
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| 关 键 词： | 甲烷 玉米秸秆 低温厌氧消化 生物强化 微生物群落 |
| 收稿时间： | 2022/11/15 0:00:00 |
| 修稿时间： | 2023/3/8 0:00:00 |
Bioaugmentation of psychrophilic methanogenic microbial consortia on psychrophilic anaerobic digestion of maize stovers |
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| ZHANG Xinjie,SUN Yongming,YAN Miao,LI Jinping,LI Ying.Bioaugmentation of psychrophilic methanogenic microbial consortia on psychrophilic anaerobic digestion of maize stovers[J].Transactions of the Chinese Society of Agricultural Engineering,2023,39(6):186-193. |
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| Authors: | ZHANG Xinjie SUN Yongming YAN Miao LI Jinping LI Ying |
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| Institution: | 1. College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou 730050, China; 2. Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; 3. CAS Key Laboratory of Renewable Energy, Guangzhou 510640, China; 4. Gansu Key Laboratory of Complementary Energy System of Biomass and Solar Energy, Lanzhou 730050, China;1. College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou 730050, China; 4. Gansu Key Laboratory of Complementary Energy System of Biomass and Solar Energy, Lanzhou 730050, China |
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| Abstract: | Abstract: A large number of maize stover can be generated per year in recent years. Sustainable treatments of maize stover can be expected to produce the renewable energy. Among them, anaerobic digestion is a friendly biotechnology to recover the renewable energy from maize stover. Especially, the psychrophilic anaerobic digestion can only require less energy input, compared with the commonly-used mesophilic and thermophilic digestors. However, a psychrophilic environment can inhibit the microbial activity, causing the low efficiency of methane production. In this study, the bioaugmentation of psychrophilic propionate-degrading consortia (the mixture of propionic-degrading consortia and acetogenic methanogen) was conducted to boost the anaerobic digestion of corn straw in psychrophilic batch reactors, with the different dosages of 3%, 6%, 9%, 12%, 15%, and 18% at low temperature (20°C). The concentrated indigenous inoculum with the dosage of 18% was introduced as the control. The reactor performance, microbial metabolites, and microbial community dynamics were analyzed to investigate the optimum dosage and mechanism. The results showed that the bioaugmentation consortia was improve the methane production rate under a psychrophilic anaerobic environment, as evidenced by 1.3 to 2.4 times increase in the bioaugmented groups, compared with the control (without bioaugmentation). The bioaugmentation dosage in the range of 3% to 12% was positively correlated with the methane yields. The optimal dose was 12%, with the methane yields of 134.1 mL/g VS. The accumulative methane yield was 1.4 times higher than that of the control. By contrast, there was no increase in the methane yields within the higher bioaugmentation dosage (i.e., 15%-18%). The modified Gompertz model showed that the concentrated indigenous inoculum was reduced the lag phase from 12.5 to 3.50 days, indicating the necessity of bioaugmentation with the key microbial consortia to boost the methane yields. Bioaugmentation inocula with the propionate-degrading consortia was shorten the lag phase from 12.5 to 0.716 days, whereas, there was the increase in the maximum methane production rate from 2.45 to 17.93 mL CH4/(gVS·d). Meanwhile, the psychrophilic environment was caused the acetate accumulation up to 4.43 g/L. At the same time, the propionate concentrations were kept at 3.88 g/L in the control reactor in the whole experimental process. Conversely, the bioaugmentation with psychrotrophic propionate-degrading consortia was accelerated the VFAs degradations, especially the acetate and propionate, which was 53.03%-90.71% less than that of the control reactor. Moreover, the acetate and propionate were fully degraded within the first 9 days in the bioaugmented reactors with 9%-15% dosage, indicating the important role of bioaugmented consortia in the scavenging propionate and acetate. Microbial analysis showed that the bioaugmentation increased the relative abundance of taxa (e.g., Proteocatella, Smithella, Peptococcaceae) for the hydrolysis and acetogenesis process. The dominant methanogens in the bioaugmented reactors were represented by acetoclastic methanogens (i.e., Methanothrix and Methanosarcina) and hydrogenotrophic methanogen (Methanobrevibacter), indicating the key contributions to increase the methane yield under psychrotrophic environment. Consequently, the bioaugmentation consortia can generate a domino effect, where acetate levels were reduced first and other VFAs degradation became thermodynamics feasible, leading to the balance between VFAs degradation and methane production. This finding can provide the evidence and guidance to improve the psychrophilic anaerobic digestion through bioaugmentation. |
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| Keywords: | methane maize stover psychrophilic anaerobic digestion bioaugmentation microbial community |
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