窖泥高产己酸菌的分离筛选及发酵性能测试

通过对老窖泥的多次富集培养，从中筛选高产己酸的菌株，并通过形态观察及分子生物学技术对其进行鉴定。同时，选取己酸产量最高的菌株进行发酵性能的测定。结果表明，从3#老窖泥中筛选并鉴定得到3株高产己酸的克鲁维氏梭菌（Clostridium kluyveri）A-1、A-3、A-5，己酸产量分别为5.73 g/L、9.77 g/L、7.45 g/L。其中Clostridium kluyveri A-3的己酸产量最高，生长周期为88.5 h，其产己酸的最佳初始pH值为7.0，发酵时间为14 d，发酵温度为37 ℃，乙醇含量为2%。pH耐受范围为3.0～11.0，温度耐受范围为13～55 ℃，乙醇最高耐受含量为5%。

Isolation,screening and fermentation performance test of high-yield caproic acid bacteria from pit mud

Through enrichment and cultivation of aged pit mud, high-yield caproic acid strains were screened and identified by morphological observation and molecular biological techniques. At the same time, the strain with the highest caproic acid yield was selected to determine fermentation performance. The results showed that three strains of Clostridium kluyveri A-1, A-3 and A-5 with high caproic acid yield were screened and identified from 3# aged pit mud, and the yield of caproic acid was 5.73 g/L, 9.77 g/L and 7.45 g/L, respectively. Among them, the caproic acid yield of the C. kluyveri A-3 was the highest, and the growth period was 88.5 h. The optimum caproic acid production conditions for C. kluyveri A-3 were initial pH value 7.0, fermentation time 14 d, temperature 37 ℃, and ethanol content 2%. The pH tolerance ranged from 3.0 to 11.0, the temperature tolerance ranged from 13 to 55 ℃, and the maximum ethanol tolerance content was 5%.