末端产物对乙醇型发酵菌群产氢能力及代谢进程的影响

Effects of Terminal Products on Hydrogen Production by Ethanol Hydrogen-Producing Microflora

利用连续流搅拌槽式反应器(CSTR)在一定条件下驯化成功的乙醇型产氢发酵菌群,通过静态培养实验,以葡萄糖为碳源,利用缓冲液控制反应体系pH值,通过不同的pH值环境使产氢发酵菌群末端产物生成比例发生改变,考察了不同的末端产物生成比例对菌群产氢能力的影响.结果表明,在液相末端产物总量相当的情况下,乙醇生成比例高时氢气产量也较高.通过外加乙醇和乙酸进行静态产氢实验发现,乙醇对发酵产氢的抑制作用不明显,同对照组相比,外加40 mmol/L时氢气产量仅下降了34%,而乙酸的存在对菌群的发酵产氢有较强的抑制,外加乙酸浓度为10 mmol/L时即对产氢发酵产生明显抑制,浓度为40 mmol/L时产氢量较对照组降低了84.3%,液相末端产物也大幅降低,混合菌群最终形成乙醇型发酵应是菌群自然选择的结果.

The effects of terminal products on hydrogen production were conducted in continuously stirred tank reactor （CSTR） by the acclimated ethanol hydrogen-producing bacteria. Glucose was added as carbon source and different ambient pH was carried out by buffer solution. High ethanol production was simultaneously achieved with high hydrogen production. The addition of 40mol/L ethanol or acetic acid can result in the reduction of hydrogen production, the former was 34 % and the latter was 84.3 %. The ethanol fermentation formation for mixed microflora was attributed to the natural selection.