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.
