Abstract
ABSTRACTA total of 142 presumptive lactococci were isolated from 40 raw milk samples and screened for bacteriocin production. Four presumptive lactococci isolates (YB23, YB42, YB98 and YB112) exhibited antimicrobial activity against indicator strains. Antimicrobial activity and protease sensitivity assays showed that a strain, YB23, produced bacteriocin that inhibited a broad spectrum of Gram-positive bacteria, and was selected for further analyses. It was identified as Lactococcus lactis subsp. lactis, phenotypically by the API system and genotypically by 16S rDNA homology. YB23 was tested for determination of antimicrobial activity against indicator strains including known bacteriocin producing lactococci and it showed no activity against nisin producer Lactococcus lactis SIK83. Different pH and heat treatments showed that the bacteriocin produced by L. lactis subsp. lactis YB23 exhibited a similar behavior with nisin produced by L. lactis SIK83. The bacteriocin produced by YB23 strain was characterized as nisin by PCR analysis of its genomic DNA. Lactic acid production and proteolytic activity in strain YB23 were determined as 0.38% and 25.3 μg Tyr/mL, respectively.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
