基因组改组选育氨肽酶和自溶度高的植物乳杆菌

Genome shuffling leads to autolytic activity and aminopeptidase activity improvement in lactobacillus plantarum

利用基因组改组方法筛选出促进干酪成熟的非发酵剂乳酸菌。采用紫外线和亚硝基胍两种传统的诱变方法对植物乳杆菌进行诱变,通过检测自溶度、氨肽酶、产酸能力指标获得6株氨肽酶活性和自溶度均有所提高的突变菌株。以获得的突变菌株为出发菌株,应用灭火双亲原生质体融合后致死损伤得到的互补获得活性融合子的方法,对其进行基因组改组,经自溶度、氨肽酶、产酸能力筛选,获得1株遗传性能稳定的菌株,其氨肽酶活力为34.01个酶活单位,比出发菌株提高了3.09倍,自溶度为56.45%,比出发菌株提高了3.16倍。

Non-starter lactic acid bacteria can be used to accelerate cheese ripening, two important factors of cheese ripening are Autolytic activi- ty and Anfinopeptidase activity. The purpose of the study is to screening out non-starter lactic acid bacteria by genome shufling. First lacto- bacillus plantarum was mutagenesis by UV and NTG, six populations of high Aminopeptidase activity were obtained. Parental protoplasts were inactivated and fused by polythyiene glycol 6 000. The fusants grew at the RaM plates were the shuffled strains.The results of switching over generation four show that they were genetic stability, producing 3.09 times as content of lactobacillus plantarum A-1.Autolysis 56.45% degrees, producing 3.16 times as content of lactobacillus plantamm A-1