Analysis of Physicochemical Properties and Whole Genome Sequencing of Anti-Staphylococcus aureus Weissella confusa Bacteriocin
[Objective]This study was aimed to screen a lactic acid bacteria producing bacteriocin resistant to Staphylococcus aureus,analyze the physicochemical characteristics of the bacteriocin produced by the strain,and analyze the whole genome sequencing of the strain.[Method]In this study,lactic acid bacterum producing antibacterial substances was screened from oranges in Yanbian city,Jilin province,using Staphylococcus aureus as an indicator strain.Morphological observation and similarity identification were performed on the selected strain,and a phylogenetic tree was constructed.Preliminary analysis of the antibacterial substances was carried out by acid excretion,hydrogen peroxide excretion and protease sensitivity tests,and the tolerance of the antibacterial substances to temperature and ultraviolet light was determined.Whole genome sequencing and function was performed on the strains.[Result]One strain of lactic acid bacteria producing antibacterial substances against Staphylococcus aureus was obtained named as LMM-1,which showed milky white,smooth and moist round colonies on MRS solid medium.After Gram staining,the bacteria were short rod positive under the oil microscope.The nucleic acid sequence was identified by 16S rRNA to be 99.86％similar to the Weissella conf use,it was confirmed that LMM-1 was Weissella confuse.The antibacterial activity of the fermentation supernatant was significantly higher than that of control group when the organic acid was excluded,and the antibacterial activity of antibacterial products of the isolate was almost unchanged when the hydrogen peroxide was excluded.The interference of organic acid and hydrogen peroxide could be excluded.And the inhibitory effect of protease treatment of antibacterial products of the isolate on Staphylococcus aureus was reduced.It still had good antibacterial activity under high temperature of 100 ℃,pH 2.0-8.0 and ultraviolet irradiation for 2 h.The length of LMM-1 genome was 2 194 218 bp,2 045 genes were predicted,and the average GC content of the genome was 44.97％.GO functional enrichment analysis results showed that the catalytic activity in molecular functions and the metabolic processes in biological processes obtained the most genomic functional annotations,with 905 and 801,respectively.KEGG pathway enrichment analysis results showed that there were 49 metabolic pathways in genetic metabolism,genetic information processing and environmental information processing,and a total of 1 050 genes were functionally annotated.[Conclusion]The bacteriocin produced by the Weissella confusa LMM-1 had a good antibacterial activity against Staphylococcus aureus,and the bacteriocin had a certain ability of acid and alkali resistance,high temperature and ultraviolet light,and had a good adaptability to the environment.The isolated strain contained many genes related to catalytic activity and metabolism.The result of this study laid a good foundation for the development of anti-Staphylococcus aureus replacement antibody products.
万方数据
