常压室温等离子体诱变选育高产酸植物乳杆菌

Breeding of high-yield acid Lactobacillus plantarum by atmospheric and room temperature plasma mutagenesis

采用常压室温等离子体(ARTP)对从酸马奶中筛选的植物乳杆菌(Lactobacillus plantarum)YL15进行诱变,选育出产酸能力高并且发酵性能稳定的乳酸菌菌株,并对其遗传稳定性及最适生长温度和最适pH进行研究。结果表明,通过单因素试验确定最佳诱变条件为在120 W照射100 s,致死率为91.09%。通过溶钙圈法和酸度测定筛选出目标菌株YL15-4。初始菌株YL15产酸量为10×10-3 mol/L,诱变菌株YL15-4与初始菌株YL15相比较,其产酸能力提高了50%,产酸量达到15×10-3 mol/L,其最适生长温度和最适生长pH值分别37℃、5.0,并且遗传稳定性良好。

The Lactobacillus plantarum YL15 selected from sour horse milk was mutated by atmospheric and room temperature plasma(ARTP).The lactic acid bacteria with high acid-producing ability and stable fermentation performance were selected,and the genetic stability,optimal growth temperature and pH were studied.The results showed that the optimal mutagenic conditions were determined by single factor experiments as follows:microwave power 120 W and time 100 s,and the lethality rate was 91.09%.The acid-producing target strain YL15-4 was screened by calcium thawing method and acidity test.The genetic stability,optimum growth temperature and optimal pH were studied.The acid production of the original strain YL15 was 10×10-3 mol/L,and the acid production ability of mutated strain YL15-4 increased 50%,which reached 15×10-3 mol/L.The optimum growth temperature and pH were 37℃and 5.0,respectively,and the genetic stability of the strain was good.