Abstract：To identify the rate-limiting degree of hydrogen-producing acetogenesis and methanogenesis in anaerobic digestion, anaerobic activated sludge sampled from an UASB was cultivated at 37℃ with a series of initial pH ranged from 5.00 to 9.00. With butyric acid, acetic acid and H2/CO2 as substrate, respectively, the ecological amplitude of pH and the substrate conversion rate of syntrophic butyrate-oxidizing bacteria (SBOB), aceticlastic methanogens (ACM) and hydrogenotrophic methanogens (HTM) were evaluated according to the Shelford's tolerance law. The results showed that the ecological amplitudes of pH for SBOB, ACM and HTM were 6.19~8.59、5.50~7.74 and 4.39~9.23, with an optimal pH of 7.39, 6.62 and 6.81 for their metabolism, respectively. With the optimal metabolic pH, the specific conversion rate of butyric acid, acetic acid and H2/CO2 by the sludge was 0.86, 1.04 and 1.09gCODequ/(gMLVSS·d), respectively. Obviously, the hydrogen-producing acetogens had narrower pH ecological amplitude and lower substrate conversion rate than the methanogens, indicating that hydrogen-producing acetogenesis in the anaerobic activated sludge had a stronger limitation on the anaerobic digestion.
王祥锟, 闵祥发, 李建政, 张玉鹏. 产氢产乙酸和产甲烷反应对厌氧消化的限速作用[J]. 中国环境科学, 2016, 36(10): 2997-3002.
WANG Xiang-kun, MIN Xiang-fa, LI Jian-zheng, ZHANG Yu-peng. Rate-limiting of hydrogen-producing acetogenesis to anaerobic digestion compared with methanogenesis. CHINA ENVIRONMENTAL SCIENCECE, 2016, 36(10): 2997-3002.
Kwietniewska E, Tys J. Process characteristics, inhibition factors and methane yields of anaerobic digestion process, with particular focus on microalgal biomass fermentation [J]. Renewable and Sustainable Energy Reviews, 2014,34:491-500.
任南琪,王爱杰,马放.产酸发酵微生物生理生态学 [M]. 北京:科学出版社, 2005.
Whitman W B, Bowen T L, Boone D R. The Methanogenic Bacteria [M]//The Prokaryotes. Springer Berlin Heidelberg, 2014:123-163.
Kato S, Yoshida R, Yamaguchi T, et al. The effects of elevated CO2 concentration on competitive interaction between aceticlastic and syntrophic methanogenesis in a model microbial consortium [J]. Frontiers in Microbiology, 2014,5:Article 575.
Ueno Y, Yamada K, Yoshida N, et al. Evidence from fluid inclusions for microbial methanogenesis in the early Archaean era [J]. Nature, 2006,440(7083):516-519.
Liu Y, Whitman W B. Metabolic, phylogenetic, and ecological diversity of the methanogenic archaea [J]. Annals of the New York Academy of Sciences, 2008,1125(1):171-189.
Worm P, Müller N, Plugge C M, et al. Syntrophy in methanogenic degradation [M]. (Endo) symbiotic Methanogenic Archaea. Springer. 2010:143-173.
Li J, Ban Q, Zhang L, et al. Syntrophic Propionate Degradation in Anaerobic Digestion: A Review [J]. International Journal of Agriculture & Biology, 2012,14(5):668-673.
Kato S, Watanabe K. Ecological and evolutionary interactions in syntrophic methanogenic consortia [J]. Microbes and Environments, 2010,25(3):145-151.
Tang Y Q, Shigematsu T, Morimura S, et al. Dynamics of the microbial community during continuous methane fermentation in continuously stirred tank reactors [J]. Journal of Bioscience and Bioengineering, 2015,119(4):375-383.
Plugge C M, van Lier J B, Stams A J M. Syntrophic communities in methane formation from high strength wastewaters [M]//Microbes at Work. Springer Berlin Heidelberg, 2010:59-77.
Angelidaki I, Sanders W. Assessment of the anaerobic biodegradability of macropollutants [J]. Reviews in Environmental Science & Bio/Technology, 2004,3(2):117-129.
Ai B, Li J, Chi X, et al. Effect of pH and buffer on butyric acid production and microbial community characteristics in bioconversion of rice straw with undefined mixed culture [J]. Biotechnology and Bioprocess Engineering, 2014,19(4):676-686.
American Public Health Association. Water Environment Federation [M]. Standard Methods for the Examination of Water and Wastewater, 1995,19.
Owen W F, Stuckey D C, Healy J B, et al. Bioassay for monitoring biochemical methane potential and anaerobic toxicity [J]. Water Research, 1979,13(6):485-492.
ter Braak C J F, Looman C W N. Weighted averaging, logistic regression and the Gaussian response model [J]. Vegetatio, 1986, 65(1):3-11.
Ban Q, Li J, Zhang L, et al. Quantitative analysis of previously identified propionate-oxidizing bacteria and methanogens at different temperatures in an UASB reactor containing propionate as a sole carbon source [J]. Applied Biochemistry and Biotechnology, 2013,171(8):2129-2141.
Müller N, Worm P, Schink B, et al. Syntrophic butyrate and propionate oxidation processes: from genomes to reaction mechanisms [J]. Environmental Microbiology Reports, 2010,2(4): 489-499.