【作者】 马超；

【导师】 李建政；

【作者基本信息】 哈尔滨工业大学 ， 微生物学， 2008， 硕士

【摘要】 在参与厌氧生物处理的各微生物类群中,产氢产乙酸菌群在营养生态位上位于产酸发酵菌群和产甲烷菌群之间,在功能生态位上起到承上启下的重要作用。它能将产酸发酵菌群代谢产生的丙酸、丁酸、戊酸等挥发性有机酸和乙醇等进一步降解转化为乙酸和CO₂、H₂,不仅为后续的产甲烷菌群提供了可以直接利用的底物,同时解除了底物对其生长和代谢的限制。产氢产乙酸代谢活性作用的增强,有望使厌氧生物处理系统的效能得到显著提高。论文以四格室的厌氧折流板反应器（ABR）第二和三格室中的厌氧活性污泥为出发菌群,进行了产氢产乙酸优势菌群的富集选育。通过丙酸和丁酸混合培养基的富集,获得了H82和H83两个产氢产乙酸菌和产甲烷菌为优势的混合菌群。研究发现,H83菌群对丙酸的降解能力优于H82菌群,而且H83菌群对丙酸和丁酸的降解速率存在显著差异。以H83菌群为初发菌群,分别接种到丙酸培养基和丁酸培养基中,进行多次传代富集培养后,分别获得了B83菌群和D83菌群,并分别考察了H83菌群、B83菌群和D83菌群的底物降解特性。借助于生理生化试验和DGGE分子生物学手段对D83菌群结构稳定性进行分析,结果表明,经过7次传代富集培养,D83菌群结构基本稳定;对葡萄糖、蔗糖、丙酸有一定的降解能力,但不能降解乙醇和乳酸。在以酸水解酪蛋白为氮源时,D83菌群对丁酸的降解能力最强,平均降解速率高达518.1 mg/L·d;以氯化铵为氮源,以丁酸为碳源时,D83菌群的生长最为旺盛,可达20.5 mgMLVSS/L·d。D83菌群的生长和对丁酸的降解符合非抑制型Monod方程。更多还原

【Abstract】 Among the bacteria colony in anaerobic organic wastewater treatment system, hydrogen-producing acetogens （HPA） connect acidogenic fermentation bacteria with methanogens in functional niche. They can convert interim products such as ethanol, propionic acid, and butyric acid into acetic acid, H₂ and CO₂, which can be metabolized directly by methanogens to methane. This results in relieving the restriction for metabolism of HPA in the meantime. The efficiency of anaerobic organic wastewater treatment system would be improved by enhancing the hydrogen-producing acetogensis. Microorganism communities dominated by hydrogen-producing acetogens were enriched and bred from the anaerobic activated sludge in an anaerobic baffled reactor （ABR） in this paper.Two mixed cultures, i.e. H82 and H83, dominated by HPA and methanogens were obtained firstly, enriched step by step in selective medium incloding propionic acid and butyric acid as carbon sources. The results indicated that H83 had better degradation ability for propionic acid than H82. Farther more, the degrading ratioes for propionic acid and butyric acid were different remarkably in H83. Enriched in propionic acid and butyric acid mediums respectively up to four times, two mixed cultures, named B83 and D83, were bred. B83 and D83 were both dominated by HPA and their metabolic characteristics were made out partly.According to the results of physiological and biochemical test and denaturing gradient gel electrophoreses （DGGE） analysis, the community structure of D83 was perfect after bred for seven times reculture. D83 could degrade glucose, sucrose and propionic acid, but not ethanol and lactic acid. When D83 was cultured with amicase casein acid hydrolysate as nitrogen source, a degrading ratio for butyric acid as high as 518.1 mg/L·d was reached. A cell multiplication ratio of 20.5 mg/L·d was obtained for D83 with ammonium chloride as nitrogen source and butyric acid as carbon source, and the growth and degradation process could characterize by Monod equation.更多还原