Induction of the bacteriocin activity in bacterial strain Lactobacillus plantarum SF15C

Abstract

Bakterije mliječne kiseline (BMK) pokazuju širok spektar antimikrobne aktivnosti. Posebni naglasak stavlja se na bakteriocine, peptide s antimikrobnim djelovanjem prema srodnim bakterijskim vrstama soja producenta i Gram-pozitivnim mikroorganizmima, koji uzrokuju kvarenje hrane i zdravstvene tegobe kod ljudi i životinja. U ovom diplomskom radu ispitivana je prisutnost gena koji kodiraju za plantaricine kod soja Lactobacillus plantarum SF15C. Isto tako ispitan je inhibitorni učinak bakterijskog soja Lb. plantarum SF15C, uzgojenog sa i bez žučnih soli, na rast test-mikroorganizma Listeria monocytogenes ATCC 19111 i Staphylococcus aureus 3048, nakon kokultivacije s istim test–mikroorganizmima. Tijekom kokultivacije također je provedeno ispitivanje bakteriocinske aktivnosti prema istim test–mikroorganizmima koji su korišteni za indukciju sinteze bakteriocina, primjenom metode s dvostrukim slojem agara.Lactic acid bacteria (LAB) show a wide spectrum of antimicrobial activity. Particular accent is on bacteriocins, peptides with antimicrobial activity against related bacterial strains and Gram-positive microorganisms that cause food degradation and health problems in humans and animals. In this graduate thesis, presence of genes, which are coding for plantaricin in the Lactobacillus plantarum SF15C was investigated. In addition, inhibitory effect of bacterial strain Lb. plantarum SF15C, grown with and without bile salts, on the growth of test organisms Listeria monocytogenes ATCC 19111 and Staphylococcus aureus 3048, after coculture with the same test microorganisms was tested. During the coculture, a bacterial activity was also tested for the same test microorganisms used to induce bacteriocin synthesis using a double-layer agar method