基于复合诱变选育高抑菌活性植物乳杆菌

为了获得高抑菌性能的乳酸菌，以植物乳杆菌DY6为出发菌株，首先对其进行常压室温等离子体（atmospheric room temperature plasma, ARTP）和亚硝基胍（nitrosoguanidine，NTG）的复合诱变，获得了抑菌活性较强的诱变菌株AN-55、AN-58及AN-68，其抑菌活性分别提高了19.83%、21.91%和18.40%。随后，经遗传稳定性实验发现菌株AN-55的抑菌性能更加稳定，8次传代后其抑菌活性较野生型菌株仍能提高20.51%。与此同时，菌株AN-55的基因组重测序结果表明plnK、cps4G、pts9D等基因序列的改变可能对提高菌株抑菌活性有重要影响，为植物乳杆菌在天然防腐剂和抗生素替代物的应用奠定了理论基础。

Breeding of Lactobacillus plantarum with High Antibacterial Activity Based on Compound Mutagenesis

In order to obtain lactic acid bacteria with high bacteriostatic property, Lactobacillus plantarum DY6 was selected as the starting strain in this study, which was mutagenized by a compound mutagenesis approach combining atmospheric room temperature plasma (ARTP) and nitrosoguanidine (NTG). The mutant strains AN-55, AN-58 and AN-68 with strong antibacterial activity were obtained, whose antibacterial activity increased by 19.83%, 21.91% and 18.40%, respectively. Subsequently, it was found that the bacteriostatic performance of strain AN-55 was more stable through the genetic stability test, and the antibacterial activity still increased by 20.51% even after 8 passages compared to the wild-type strain. At the same time, genome resequencing of strain AN-55 revealed that the changes of plnK, cps4G and pts9D gene sequences may have an important effect on improving the antibacterial activity of the strain, laying a theoretical foundation for the application of Lactobacillus plantarum as natural preservatives and antibiotic substitutes.