产氢产乙酸菌株AX2的生长条件及产乙酸特性

产氢产乙酸菌群在参与厌氧消化过程的各类微生物菌群中起着承上启下的作用,然而,目前产氢产乙酸菌的纯培养物很少,对其生理生态习性的了解也十分有限.为增加产氢产乙酸菌资源,了解其生理生化特性,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具有产氢产乙酸特性的葡萄球菌(Staphylococcus)AX2,对其生长条件及转化丙酸和丁酸为乙酸的能力进行研究.结果表明,菌株AX2在丁酸培养基(2.4 g/L)和丙酸培养基(2.31 g/L)中的乙酸产量可分别达到278 mg/L和222 mg/L,并在以氯化铵为无机氮源、pH为7.0、35℃等条件下具有最佳的增殖能力.菌株AX2对丙酸、丁酸有较强的乙酸转化能力.

Growth and acetic acid production characteristics of a new strain AX2 falling within hydrogen-producing acetogens

Among the bacteria colony in anaerobic digestion process,hydrogen-producing acetogens connect acidogenic fermentation bacteria with methanogens in functional niche.However,few pure cultures of hydrogen-producing acetogens have been obtained and knowledge about their physioecologic characteristics is little.Strain AX2,a new hydrogen-producing acetogen,belongs to Staphylococcus had been separated from anaerobic activated sludge.Its physioecologic character was investigated by batch culture.The acetic acid yields of AX2 in culture mediums of butyric acid and propionic acid with concentrations of 2.4 g/L and 2.31 g/L reached 278 mg/L and 222 mg/L,respectively.It had an excellent multiplication speed at pH of 7.0 and the temperature of 35 ℃,using ammonium chloride as the inorganic nitrogen source.The result indicates that AX2 has a strong capability to convert propinoic acid and butyric acid into acetic acid.