A screening of class IIa bacteriocins produced by lactic acid bacteria isolated from fermented mare milk.

摘要

Twelve fermented mare milk samples were screened for class IIa bacteriocins based on a polymerase chain reaction (PCR) method. The positive PCR products were cloned and sequenced. The sequences shared 99% identity to enterocin A-coding gene. The lactic acid bacteria, which showed positive PCR results, were detected with antimicrobial activity by means of traditional well-diffusion method. The strains C71 and C102 showed antimicrobial activity to L isteria sp. These strains showed a potential application in food preservation. The results also indicated the PCR screening method proposed in this study can be used for the screening of antimicrobial peptides of class IIa. Practical Applications. In the present study, 44 class IIa bacteriocins from a wide range of lactic acid bacteria were included in a cluster analysis, and primers were designed on basis of the cluster analysis. We screened class IIa bacteriocin-producing lactic acid bacteria that were isolated from traditional fermented mare milk by means of a PCR-based assay. Two strains showed potential application in food preservation. The results indicated the PCR screening method proposed in this study can be used for the screening of antimicrobial peptides of class IIa. This method is still in an exploratory stage. It needs to be improved in the future