Shift of pathways during initiation of thermophilic methanogenesis at different initial pH
Shift of pathways during initiation of thermophilic methanogenesis at different initial pH
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不同初始pH下嗜热产甲烷启动过程中的途径转变
DOI：
10.1016/j.biortech.2011.12.072
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发表时间：
2012-12-01
影响因子：
11.4
通讯作者：
He, Pin-Jing
中科院分区：
文献类型：
--
作者：
Hao, Li-Ping;Lu, Fan;He, Pin-Jing
为研究酸危机启动产甲烷过程中的代谢途径，采用同位素标记和选择性抑制法，结合微生物结构分析，研究了初始pH（5.0-6.5）对100 mmol/L乙酸盐高温产甲烷转化的影响.结果表明，低pH延长了产甲烷的滞后期，在整个培养过程中，pH 5.0抑制了产甲烷。在初始pH 6.0-6.5时，甲烷生成主要通过乙酸裂解甲烷生成（AM）启动，其中氢营养途径（f（mc））占甲烷生成总量的21-22%。相反，在初始pH 5.5时，优势途径转移到互养乙酸氧化与氢营养甲烷（SAO-HM），与f（mc）上升到51%和互养乙酸氧化细菌的丰度显着增加。当AM途径被抑制时，甲烷生成可以通过SAO-HM途径独立启动。乙酸盐氧化同养菌可能是低pH危机下甲烷生成的起始中心。(C)2011爱思唯尔有限公司版权所有。
To investigate the metabolic pathways during the initiation of methanogenesis from acid crisis, the influence of initial pH (5.0-6.5) on thermophilic methanogenic conversion of 100 mmol/L acetate was monitored based on the isotopic signature and selective-inhibition method combined with analysis of the microbial structure. The results showed, lower pH extended the lag phase for methanogenesis which was inhibited at pH 5.0 throughout the incubation. At initial pH 6.0-6.5, methanogenesis was primarily initiated via acetoclastic methanogenesis (AM), with the fraction of the hydrogenotrophic pathway (f(mc)) accounting for 21-22% of total methane formation. Conversely, at initial pH 5.5, the dominant pathway shifted to syntrophic acetate oxidation coupled with hydrogenotrophic methanogenesis (SAO-HM), with f(mc) rising to 51% and the abundance of syntrophic acetate-oxidizing bacteria increasing remarkably. Methanogenesis could initiate independently via SAO-HM pathway when AM pathway was inhibited. Acetate-oxidizing syntrophs could function as the initiation center of methanogenesis from low-pH crisis. (C) 2011 Elsevier Ltd. All rights reserved.