Lactic acid bacteria strains isolated from Sjenica cheese

Abstract

Lactic acid bacteria strains isolated from autochthonous cheeses of Sjenica were investigated. In those products, where starters were not added fermentation occurred as a result of natural flora present in the surrounding environment. Forty thermophilic, mesophilic and citrat+ LAB strains were isolated by selective mediums (MRS agar, LM17 agar and LDC agar) from 5 samples of Sjenica-cheeses. They were exposed to further analysis and identification. After examination by Gram test and catalase test, 13 strains of LAB, were selected for further analysis. On the basis of lactose fermentation way and acid production in 1% reconstituted skimed milk, 6 strains were selected. Determination of these strains by API 50 CHL and Rapid ID 32 Strep tests showed that 2 strains belonged to the Lactococcus lactis ssp. lactis, 2 strains to the Lactococcus lactis ssp. cremoris and 2 strains to the Lactobacillus para.paracasei.

U radu su izolovani i karakterisani sojevi bakterija mlečne kiseline izdvojeni iz sjeničkog sira, proizvedenog autohtonom tehnologijom, bez dodavanja starter kultura. Iz 5 uzoraka sjeničkog sira izvršena je izolacija 40 termofilnih, mezofilnih i citrat+ sojeva BMK na odgovarajućim selektivnim podlogama (MRS agar, LM17 agar i LDC agar). Ovi sojevi su dalje podvrgnuti ispitivanju na Gram reakciju i katalaza test, posle čega je izabrano 13 sojeva za dalja ispitivanja. Na osnovu načina fermentacije laktoze i acidogene sposonosti praćene u 1% rekonstituisanom obranom mleku selekcionisano je samo 6 sojeva. Determinacijom ovih sojeva pomoću API CHL 50 i Rapid ID 32 Strep testa, pokazalo se da 2 soja pripadaju vrsti Lactococcus lactis ssp. lactis, 2 soja Lactococcus lactis ssp. cremoris i 2 soja vrsti Lactobacillus para.paracasei.