Physicochemical Properties of Lactic Acid Bacteria Bacteriocin against Main Pathogenic Bacteria of Cow Mastitis
The aim of this study was to identify the bacteria strain LQY-4 which produces antibacterial active substances against the main pathogens causing mastitis in dairy cows,and to conduct a preliminary investigation into the biological characteristics of the antibacterial substances it secretes,in order to lay a solid foundation for the development of novel alternatives for treating mastitis in dairy cows.Strains were identified by morphological,biochemical tests and 16S rRNA gene sequencing.Escherichia coli as the indi-cator bacteria,the agar well diffusion method was used to determine the antibacterial activity of the fer-mented supernatant,and protease susceptibility test,heat treatment as well as acid-base treatment test were performed to determine the biological characteristics of the antibacterial active substances,and final-ly,the determination of the inhibition spectrum was performed.Results showed that the isolated strain LQY-4 was identified as Lactiplantibacillus plantarum,and its fermented supernatant exhibited good an-tibacterial activity against major pathogens of mastitis(Escherichia coli,Staphylococcus aureus,True-perella pyogenes).Moreover,it showed high sensitivity to proteases,so that the substance with antibac-terial activity in its primary extract was assumed to be a bacteriocin.In conclusion,the substance of L.plantarum LQY-4 demonstrates better thermal and acid stability,making it a promising alternative to an-tibiotics for the treatment of mastitis in dairy cows.
万方数据
维普
