丁酸梭菌紫外诱变选育高产丁酸菌株及其耐受性分析

Breeding of High-Butyric Acid Producing Strain by Ultraviolet Mutagenesis of Clostridium butyricum and Its Tolerance Analysis

为了筛选耐受性较好、高产的丁酸梭菌菌株,试验采用紫外诱变的方法使菌株产生突变,通过平板初筛、发酵复筛,得到了一系列较出发菌株丁酸产量高的菌株,分析其对温度、模拟胆盐、模拟肠液的耐受性。结果表明:D2-3菌株丁酸产量最高,达到3.23 g/L,较出发菌株的丁酸产量(2.11 g/L)提高53.08%。连续培养7代后其丁酸产量为3.16 g/L,产酸能力稳定。在80℃处理10 min、0.5%胆盐处理2 h、模拟肠液处理2 h、模拟胃液处理2 h条件下,D2-3菌株的存活率分别93.27%、91.32%、99.16%、92.42%,显著高于出发菌株(P<0.05)。说明诱变菌株D2-3具有较高的丁酸产量,且对温度、胆盐模拟肠液、模拟胃液有较好的耐受性。

The purpose of this study is to screen high-butyrate-producing Clostridium butyricum strain.The strain was mutated by ultraviolet mutagenesis,and a series of strains with higher butyric acid produc⁃tion than the original strain were obtained through primary screening on plates and secondary screening by fermentation.The strain numbered D2-3 had the highest ability to produce butyric acid.Butyric acid production of 3.23 g/L was 53.08%higher than that of the starting strain(2.11 g/L).After 7 generations of continuous culture,the butyric acid production was 3.16 g/L,and the acid production capacity was sta⁃ble.Under the conditions of 10 minutes at 80℃,2 h with 0.5%bile salts,2 h with simulated intestinal fluid,and 2 h with simulated gastric juice,the survival rates of D2-3 strains were 93.27%,91.32%,99.16%,and 92.42%,which were higher than the original strains(P<0.05).In summary,the mutagenized strain D2-3 had a high yield of butyric acid and a good tolerance to temperature,bile salt simulated in⁃testinal fluid,and simulated gastric fluid.