CSTR系统发酵产氢细菌群落动态与产氢能力关系解析

Analysis of Dynamic Characteristics for Fermentative Hydrogen-producing Bacteria Community and Hydrogen Producing Capability in CSTR

将CSTR系统内pH由4.2一次性提高至6.0左右,启动发酵类型的转化,研究了转化过程系统内的产氢动态和细菌群落.结果表明,在有机负荷维持在(33±1)kg/(m3.d)的情况下,发酵类型10d内未发生改变,产氢量8d内未降低,15d后系统内种群由乙醇型转化为丁酸型,进水碱度由250mg/L增至2450mg/L.研究中利用荧光原位杂交技术(FISH)对反应系统内3类微生物群进行监测发现,在转化过程中Clostridium cluster XI数量增加,Clostridium clusterⅠ和Ⅱ数量减少,而Enterobacteriaceae始终存在,变化不明显.种群的消长同反应系统产氢能力的高低存在密切关联,以Clostridium clusterⅠ和Ⅱ占优势的乙醇型发酵具有更佳的产氢能力,平均比产氢速率为23.6mol/(kg·d).

The start into the types of fermentation was carried out by pH adjustment from 4.2 to 6.0 in CSTR system. The process of transforming of hydrogen production and dynamic community of bacteria were studied. The results showed that with the organic load maintained at （33±1 ） kg/（m^3 · d）, there was no change in 10 d for the type of fermentation, the amount of hydrogen does not reduce in 8 d. After 15 d, the system was transformed from the ethanol-based type into butyric acid type and water alkalinity was from 250 mg/L to 2 450 mg/L. The use of fluorescence in situ hybridization （FISH） system was in response to the 3 groups of micro-organisms. It was found that in the process of transforming, Clostridium cluster Ⅺ increases and Clostridium cluster Ⅰ and Ⅱ decreases. Enterobacteriaeeae always existed with no change. The microbial growth must be considered with hydrogen production capability. The average hydrogen production rate reached to 23.6 mol/（kg·d） with Clostridium cluster Ⅰ and Ⅱ dominated in fermentation reactor.