同型产乙酸菌株CA3及其发酵葡萄糖产乙酸条件优化

 同型产乙酸菌纯培养物的获得,可为研究其在厌氧生物处理系统中的生理生态功能以及生产化工溶剂乙酸提供种质资源。以CO₂为碳源,采用改良Hungate厌氧技术,从厌氧活性污泥中分离得到一株同型产乙酸菌CA3。该菌株为严格厌氧,卵形,G⁺,可利用H₂/CO₂产乙酸,也能发酵葡萄糖、果糖等产生乙酸。16SrRNA基因序列比对及系统发育树构建结果表明,CA3隶属Blautia sp.。菌株CA3能在20~45℃的温度范围内生长,最适生长温度为35℃,最适初始pH值为8.0。在最适条件下,菌株CA3利用H₂/CO₂产乙酸速率可达8.92mg/(L·h);以酵母粉作为氮源发酵葡萄糖时,发酵体系的乙酸浓度可达1370mg/L。

Homoacetogenic Strain CA3 and Its Optimization Condition for Acetate Yield from Glucose by Fermentation

Germplasm resources of homoacetogens are not only the basis for the production of chemical solvent acetic acids but also important for investigating their ecophysiological functions in anaerobic digestion systems. With CO₂ as the carbon source, an anaerobic bacterium strain CA3 was isolated from the anaerobic activated sludge by the modified Hungate anaerobic technique. The strain CA3 is a strictly anaerobic, gram-positive and oval-shaped acetogenic bacterium. This bacterium could metabolize H₂/CO₂ to acetate, and was able to ferment glucose and fructose with acetate as a major product. The phylogenetic analysis based on 16SrRNA gene sequence indicates that the strain CA3 affiliates to the genus Blautia sp.. This strain could grow with temperature in the range from 20℃ to 45℃. With the optimum temperature of 35℃ and the initial pH value of 8.0, an acetate producing rate of 8.92mg/(L·h) was obtained in its pure culture with H₂/CO₂ as the carbon source. The most feasible nitrogen source for the strain CA3 to ferment glucose is the yeast extract and the acetate producing rate reaches 1370mg/L in its pure culture.