Self-adaption of methane-producing communities to pH disturbance at different acetate concentrations by shifting pathways and population interaction

详细信息    查看全文

• 作者：Liping Hao ; Fan L¨¹ ; Lei Li ; Qing Wu ; Liming Shao ; Pinjing He
• 关键词：Syntrophic acetate oxidation ; Acetoclastic methanogenesis ; High acetate concentration ; Methyl fluoride ; Thermophilic anaerobic digestion
• 刊名：Bioresource Technology
• 出版年：2013
• 出版时间：July, 2013
• 年：2013
• 卷：140
• 期：Complete
• 页码：319-327
• 全文大小：538 K

文摘

To investigate the competition among acetate-utilizing microorganisms at different acetate levels, bioconversion processes of 50, 100, 150 and 200 mM acetate in the presence and absence of methanogenic inhibitor CH₃F were monitored in thermophilic methanogenic system. The successive response of methane-producing community during the deteriorative and recovery phases caused by pH disturbance was analyzed. High acetate concentration (>50 mM) inhibited the activity of acetoclastic methanogenesis (AM). The increasing pH (>7.5) enhanced this inhibition. The syntrophic acetate oxidizing (SAO) bacteria and hydrogenotrophic methanogens including Methanomicrobiales and Methanobacteirales were more tolerant to the stress from high acetate concentration and high pH. Resumption from alkali condition to normal pH stimulated the growth of acetate oxidizing syntrophs. The reaction rate of SAO-HM was lower than that of AM. These results point to the possibility to regenerate the deteriorated anaerobic digesters by addition of acclimatized inocula rich in acetate-oxidizing syntrophs.