Breeding of broad-spectrum bacteriocin-producing lactic acid bacteria in traditional fermented dairy products
To breed broad-spectrum bacteriocin-producing lactic acid bacteria,96 strains of lactic acid bacteria isolated and purified from tradition fer-mented dairy products in Gansu province were screened by agar diffusion assay,and the bacteriocin-producing strains were determined.The strains with the optimal antibacterial effect were mutated by heavy ion beam 12C6+irradiation,and the broad-spectrum antibacterial performance on six indi-cator bacteria was compared by culture dish partition method.The results showed that the bactericin-producing strain Lp 1 with the optimal bacterio-static effect was selected,and 98 mutant strains were obtained by irradiation mutation.Five mutant strains(L088,L087,L063,L049,L010)with significantly better antibacterial performance against Escherichia coli,Staphylococcus aureus,Listeria monocytogenes,Salmonella,Shigella and Cronobacter were screened for broad-spectrum antibacterial performance,and were significantly better than those of the original strain Lpl.Among them,strains L088 and L063 had better broad-spectrum antibacterial performance,the radius of inhibition annular sector of the mutant strain L088 against 6 indicator bacteria increased by 47.81％,33.28％,22.97％,45.25％,21.39％,and 40.21％than that of the original strain Lp1 respectively,and the radius of inhibition annular sector of the mutant strain L063 against 6 indicator bacteria increased 54.27％,29.18％,25.37％,58.03％,17.85％,and 42.13％,respectively.The inhibition tests of 6 indicator bacteria could be completed in one Petri dish simultaneously,which could screen the broad-spectrum bacteriocin-producing lactic acid bacteria efficiently.
lactic acid bacteriabacteriocinbroad-spectrum bacteriostasisbacteriostatic test
NETL
NSTL
万方数据
维普
