产氢反应器内两种发酵类型细菌的种群结构与发酵特征

通过改变CSTR系统内pH值,启动发酵类型由乙醇型向丁酸型转化,研究了转化前后系统内产氢动态和细菌群落变迁.结果表明,在有机负荷不变的情况下,启动发酵类型转化15d后,系统内种群由乙醇型转化为丁酸型,消耗碱度量由350mg.L-1增至1720mg.L-1,平均比产氢速率由21.2mol.kg-.1d-1降低至11.1mol.kg-.1d-1.荧光原位杂交技术(FISH)对反应系统内3类微生物群的监测结果表明,未启动转化时,肠杆菌、梭菌Ⅰ、Ⅱ和梭菌Ⅺ的相对丰度分别为22%、48%和30%,转化结束后,3类细菌的相对丰度为19%、24%和55%.

Microbial community group characteristics for two types of fermentative hydrogen-production in a hydrogen producing reactor

The hydrogen-producing system and the bacterial community in a continuous stirred-tank reactor (CSTR) were studied before and after converting the process from ethanol-type fermentation to butyric acid-type by changing the pH. The results showed that the type of fermentation system transformed after 15 d from ethanol into acid-based type with organic loading unchanged. Alkalinity consumption increased from 350 mg·L-1 to 1720 mg·L-1 and the average hydrogen production rate changed from 21.2 mol·kg-1·d-1 to 11.1 mol·kg-1·d-1. Three types of microorganisms were detected in the reactor by fluorescence in situ hybridization (FISH). Before the process, the relative abundances of Enterobacter, Clostridium cluster I, II and Clostridium cluster XI were 22%, 48% and 30% compared with 19%, 24% and 55% after transformation, respectively.