Isolation of bacteriocin (Enterocin) producer enterococci strains from different type cheese and identification of bacteriocins by polymerase chain reaction (PCR)
2015
Avc?, M.
The aim of the thesis is isolation of Enterococcus strains from different kind of cheeses capable of producing bacteriocin, and identification at molecular level, determination of antimicrobial activity spectrum and determination of structural genes of bacteriocin by Polymerase Chain Raection of these bacteria (PCR). The scope of work ,100 presumptive Enterococcus strains were isolated from 33 different cheese samples. 11 isolates among the 100 isolates phenotypically defined as members of the genus Enterococcus determined that showed different activity spectrum that in the trial antimicrobial activity and study has continued with these isolates. Proteolytic enzyme study showed that antimicrobial substances produced by these isolates are protein structure. 6 isolates were identified as Enterococcus faecium and 5 isolates were identified as Enterococcus faecalis by 16S rDNA analysis. PCR treatments for molecular identification bacteriocins produced by Enterococcus strains showed that E. faecalis MBE29-1 and E. faecalis MBE29-3 has only entX, while E. faecium MBE16-5 and E. faecalis MBE31-4 has entA and entX; E. faecium MBE15-2 and E. faecium MBE 27-3 entA, entB and entX; E. faecium MBE12-3 has entA and entB; E. faecium MBE22-2 has entA, entP, and entX structural genes. E. faecium MBE27-2 strain identified as the only one producing strain that has 4 structural enterocin genes (entA, entB, entP and entX). Enterocins produced by E. faecalis MBE1-9 and E. faecalis MBE20-5 strains did not give PCR amplificiation products by the primers used in this study.
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