基于复合诱变选育高抑菌活性植物乳杆菌

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

摘要:

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。

Abstract:

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.