Methanogenic population dynamics regulated by bacterial community responses to protein-rich organic wastes in a high solid anaerobic digester
Methanogenic population dynamics regulated by bacterial community responses to protein-rich organic wastes in a high solid anaerobic digester
复制标题
高固体厌氧消化器中细菌群落对富含蛋白质的有机废物的反应调节产甲烷种群动态
DOI：
10.1016/j.cej.2017.02.098
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发表时间：
2017-06-01
影响因子：
15.1
通讯作者：
Dai, Xiaohu
中科院分区：
文献类型：
--
作者：
Li, Ning;Xue, Yonggang;Dai, Xiaohu
每年产生的大量富含蛋白质的有机废物是厌氧消化的极有价值的底物。尽管游离氨（FAN, NH3）和铵（NH4+）是迄今为止最广泛认可的影响操作稳定性的抑制剂，但在富含蛋白质的材料加工中的详细抑制机制尚不清楚。本研究旨在确定高负荷蛋白质厌氧降解引发的单一或协同效应，以期了解微生物生态系统如何响应改变的环境条件，如NH3、NH4+、醋酸盐、挥发性脂肪酸（VFA）、pH和碱度的变化。采用半连续运行的富蛋白有机废物高固厌氧沼气池，在125 d的运行过程中经历了一个完整的稳定-抑制-回收循环。通过对系统中醋酸产甲烷动力学的分析和建模，阐明了在抑制条件下产甲烷菌的生理特性。采用QIIME管道16S rRNA焦氧测序技术监测古菌和细菌在操作过程中的群落动态，并采用非度量多维标度（NMDS）分析与动力学拟合参数协调生态群落。因此，甲烷生产的抑制和恢复本质上归因于总铵态氮（TAN）、碱度和VFA（醋酸盐）的变化，因为这些因素决定了细菌群落的变化，触发了产甲烷途径从丙酮裂解向氢营养化产甲烷的转变。细菌群落的反应比产甲烷菌群落更敏感，这也表明特定的细菌种类，如T78（第38天之前）、RFN20（第40-56天）、温双微生物（第60-66天）和未分类梭状芽胞杆菌（第70天之后）可能是沼气池性能更好的生物标志物。(C) 2017 Elsevier B.V.版权所有
The large amount of protein-rich organic waste generated annually is an extremely valuable substrate of anaerobic digestion. Although free ammonia (FAN, NH3) and ammonium (NH4+) are so far the most widely acknowledged inhibitors affecting operational stability, the detailed inhibition mechanisms in the processing of,protein-rich material remain unclear. The present study aimed to determine the single or synergistic effects initiated by the anaerobic degradation of highly loaded protein, in hopes of understanding how a microbial ecosystem responds to altered environmental conditions such as changes in NH3, NH4+, acetate, volatile fatty acids (VFA), pH, and alkalinity. A high solid anaerobic digester with protein-rich organic wastes was operated semi-continuously which endured a complete stable-inhibited-recovered cycle during the whole operation of 125 days. The kinetics of methanogenesis from acetic acid (HAc) in the system was analyzed and modelled to clarify the physiologic properties of methanogens under inhibition conditions. The community dynamics of archaea and bacteria during the operation were monitored by 16S rRNA pyrosequencing following the QIIME pipeline, and nonmetric multidimensional scaling (NMDS) analysis was conducted to ordinate the ecological community with kinetics fitting parameters. As a result, the inhibition and recovery in methane production are intrinsically attributed to the changes in total ammonium nitrogen (TAN), alkalinity, and VFA (acetate), because these factors dictate the changes in a bacterial community, triggering the shift in the methanogenic pathway from acetoclastic to hydrogenotrophic methanogenesis. The more sensitive responses from the bacterial community than the methanogenic community also indicated that specific bacterial species, such as T78 (before day 38), RFN20 (days 40-56), Tepidimicrobium (days 60-66), and unclassified Clostridia (after day 70), might be better biomarkers of digester performance. (C) 2017 Elsevier B.V. All rights reserved.