抗奶牛乳房炎主要病原菌细菌素的筛选及其生物学特性分析OA北大核心

This study aimed to screen bacteriocins with antibacterial activity against the main pathogenic bacteria of bovine mastitis and analyze their biological characteristics.Lactic acid bacteria were isolated and purified from traditional Korean kimchi from Jilin City using streak plate and spread plate methods.The inhibitory activity was tested using the agar diffusion method with Staphylococcus aureus as the indicator bacterium,along with acid and hydrogen peroxide exclusion tests to preliminarily screen antagonistic strains.The antagonistic strains were identified by morphological characteristics and 16S rRNA sequence analysis.The growth and antibacterial kinetics curves of the strains were determined to establish the optimal fermentation time.The physicochemical properties of the antibacterial substances were assessed by testing their sensitivity to protease,thermal stability,and pH stability,and their antibacterial spectrum was determined.The results showed that one strain,designated MX1,capable of producing bacteriocin was isolated and identified as Lactobacillus plantarum.The optimal fermentation time was 22 hours.The bacteriocin secreted by strain MX1 exhibited good thermal and acid stability,retaining strong antibacterial activity after 2 hours of high-temperature treatment or in highly acidic environments with pH of 3.0 and 4.0.The bacteriocin produced by strain MX1 demonstrated effective antibacterial activity against the primary pathogenic bacteria of bovine mastitis,including Staphylococcus aureus,Escherichia coli,and Klebsiella pneumoniae.These results suggest that the bacteriocin obtained in this study has potential as an alternative antibacterial product for the prevention and treatment of bacterial bovine mastitis.