Antimicrobial Action of isolated Probiotic Lactobacillus plantarum from Different Fermented Dairy Products from Trabzon City

Antimicrobial properties of probiotic bacteria are so important to hinder the entrance of threatening infectious agents to the human body. İt's antimicrbial action represented by releasing some substances having antimicrobial properties such as H2O2, lactic acid, organic acids and bacteriocins.

This study was designed to secreen the antimicrobial action of fourteen L. plantarum previously chatacterized as highly potential probiotic source against some pathogen causing infection to the human.

Analytical cross section.

About fifty different fermented products were collected randomly from local markets in the Trabzon city. All samples were streaked on Deman Rogosa Agar (MRSA) media. Primary identification of the Lactobacillus strains were made based on gram staining, cell morphology, catalase and oxidase test results and carbohydrate fermentation ability of 17 sugars. Suspected Lactobacillus bacteria were subjected to different tests to evaluate their ability to act as probiotic such as tolerance to acidity, bile salt concentartion and and haemolytic activity. Finally some of highly antimicrobial action of Lactobacillus strains were genetically identified by using 16S ribosomal RNA sequence analysis and Matrix Assisted Laser Desorption/Ionization Time of Flight Mass technique (MALDI/TOF) technique

About 103 Lactobacillus strains were recovered from 50 different dairy products. All of the strains were gram-positive bacilli, oxidase and catalase negative. Finally, 14 Lactobacillus strains were revealed highly resistance to acid and high bile salt concentration and biosafety assessment (absence of haemolytic properties). All 14 strains inhibited the pathogenic bacteria by releasing of organic acid or hydrogen peroxidase or both. Based on 16S rDNA sequence analysis all fourteen strains were identified as L. plantarum species.

The fourteen L. plantarum were confirmed their antimicrobial action represented by organic acids and hydrogen peroxide production against different pathogen.