一株产氢产乙酸菌的生长条件及产乙酸特性

Characteristics of Growth and Acetic Acid Production of a New Strain of Hydrogen-producing Acetogens

在参与有机废水厌氧生物处理的各类微生物菌群中,产氢产乙酸菌群在功能生态位上起着承上启下的作用,对产氢产乙酸过程的强化,将有助于提高厌氧生物处理系统的效能。在前期研究中,通过丙酸和丁酸混合培养基,从厌氧活性污泥中筛选到一株双歧杆菌属(Bifidobacterim)的产氢产乙酸菌AX3。间歇培养试验结果表明,菌株AX3可在pH7.0、30℃条件下获得最佳增殖,不仅对丁酸和丙酸具有很高的乙酸转化率,同时也可发酵多种双糖和淀粉,并产生一定数量的乙酸。作为氮源,氯化铵比尿素更能有效地促进菌株AX3的增殖。

Among microbial colonies in anaerobic organic wastewater treatment system, hydrogen-producing acetogens play the role of a connecting link for the acidogenic fermentation bacteria and methanogens in the functional niche. They can convert interim products such as ethanol, propionic acid, and butyric acid into acetic acid, which can be directly decomposed to methane by methanogens. The increase in number and the enhancement in metabolism of hydrogen-producing acetogens see an improvement of the efficiency of anaerobic organic wastewater treatment process. However, few pure cultures of hydrogen-producing acetogens have been obtained and little is known about their physio-ecological characteristics. Strain AX3, a new hydrogen-producing acetogen belonging to Bifidobacterim, was obtained from anaerobic activated sludge, selected by a mixed culture medium of propionate and butyrate. Its physio-ecological characteristics were investigated by batch culture. The results indicate that strain AX3 has a perfect multiplication speed at pH 7.0 and 30℃, using ammonium chloride as inorganic nitrogen source and can convert propanoic acid and butanoic acid into acetic acid eficiently.