Physicochemical Properties Research of Lactiplantibacillus plantarum MU-6 Bacteriocin and Its Coding Gene Mining
[Objective]The purpose of this experiment was to study the stability of bacteriocin produced by a Lactobacillus strain and to mine its coding gene cluster.[Method]Traditional kimchi from Bayannur city,Inner Mongolia Autonomous Region was placed in MRS broth and cultured at 37 ℃ for 12 h to isolate bacteria.Salmonella Typhimurium was used as indicator bacteria for bacteriostatic tests.The isolated strains were screened and analyzed by 16S rRNA sequencing and BLAST comparison.The stability of bacteriocin produced by isolates was evaluated according to protease,temperature,pH and UV.Whole genome sequencing technology was used to obtain the genomic characteristics of isolates and explore the potential bacteriocin coding gene clusters.[Result]A Lactobacillus strain producing bactericin against Salmonella Typhimurium was screened from kimchi.Similarity comparison results showed that the isolated strain was 98％similar to Lactiplantibacillus plantarum,which was named MU-6.After the fermentation supernatant concentrate of MU-6 was treated with acid discharge the MRS inhibition zone diameter of the test group was significantly smaller than that of the blank control group.In the hydrogen peroxide exclusion experiment,the inhibition zone diameter did not change.The antibacterial activity decreased after protease treatment.The bacteriocin produced by MU-6 still had high bacteriostatic activity under 100 ℃,pH 3.0-5.0 and UV irradiation.Whole genome sequencing showed that the genome length of MU-6 was 2 782 959 bp,3 129 genes were predicted,and the GC content was 44.43％.The results of gene cluster mining showed that strain MU-6 had 7 core peptides,including Plantaricin J,Plantaricin A,Plantaricin E and Plantaricin F,and so on,most of which belonged to Class Ⅱb bacteriocins.[Conclusion]In this study,a kind of Lactiplantibacillus plantarum bacteriocin with stable physical and chemical properties and good antibacterial activity was screened,which had good antibacterial effect and had broad application prospects as a natural antiagent.
国家科技期刊平台
NSTL
万方数据
