Bacteriocin activity of autochthonous Lactobacillus plantarum strains isolated from various fermented products

Bakteriocini su mali ribosomski sintetizirani peptidi koji inhibiraju rast srodnih mikroorganizama, onemogućavanjem normalnog funkcioniranja staničnih struktura. U ovom radu proučavani su plantaricini, proizvedeni s tri različita soja Lactobacillus plantarum. Antimikrobno djelovanje sojeva ispitivano je na test-mikroorganizmima Listeria monocytogenes ATCC 19111 i Staphylococcus aureus 3048, koji su učestali patogeni. Ispitivanje antibakterijskog djelovanja plantaricina temeljeno je na dvije metode: metodi s rupama u agaru i metodi s dvostrukim slojem agara. Rezultati dobiveni navedenim metodama ukazali su na najveću inhibicijsku sposobnost soja Lb. plantarum M92C. Također, u svrhu ostvarivanja bolje spoznaje aktivnosti i funkcije plantaricina, provedena je analiza gena proučavanih triju Lactobacillus plantarum sojeva pomoću PCR metode. Pritom je PCR metodom dokazana prisutnost gena plnA, plnEF i plnJ koji kodiraju za plantaricine kod svih proučavanih Lb. plantarum sojeva.Bacteriocins are small ribosomally synthesized peptides which inhibit growth of closely related strains of microorganisms, by disrupting normal functioning of important cellular structures. In this research, we examined plantaricins produced by three different strains of Lb. plantarum. Antimicrobial activity was examined on test-microorganisms, Listeria monocytogenes ATCC 19111 and Staphylococcus aureus 3048, which are common pathogens. Assaying for plantaricin activities of three examined Lb. plantarum strains were based on two methods: agar well diffusion method and agar spot test method. Results obtained by these methods demonstrated strongest inhibitory ability of Lb. plantarum M92C. Moreover, to acquire better understanding of plantaricin activity and function, gene analysis was conducted by PCR method for three strains of Lb. plantarum that we used. PCR method demonstrated presence of genes plnA, plnEF and plnJ which code for plantaricines in all Lb. plantarum strains used in analysis