Characterization of lactic acid bacteria isolated from artisanal Zlatar cheeses produced at two different geographical location

摘要

Eighty-one strains of lactic acid bacteria (LAB) were isolated from white semi-hard homemade cheese, designated Zlatar BGNV, which was taken from household settled on Northern side of mountain Zlatar. The Zlatar BGNV cheese was manufactured from raw cow's milk without addition of the starter culture. All isolates of LAB were characterized by phenotypic and genotypic tests. Identification of strains was done by the repetitive extragenic palindromic-polymerase chain reaction (rep-PCR) with (GTG)5 primer and 16S rDNA sequence analysis. The most present species in Zlatar BGNV cheese were Lactobacillus casei/paracasei (65.43%) and Enterococcus faecalis (29.63%). Two facultative heterofermentative rods were identified as Lactobacillus plantarum (2.47%), and two obligate hetrofermentative LAB isolates as Lactobacillus parabuchneri (2.47%). Among all 81 tested isolates, only eight enterococci were producers of antimicrobial compounds. Fourteen of 16 tested lactobacilli isolates showed medium to very good proteolytic activity. All 57 lactobacilli from the Zlatar BGNV cheese curdled milk very slowly or did not curdle milk at all. However, three isolates of enterococci, BGNV1-63, BGNV1-76 and BGNV1-80, showed very good activity in milk and curdled milk within 5 h. They showed very high proteolytic activity hydrolyzing completely αs1- and κ-casein after 3 h, and β-casein after 30 min of incubation. In addition, those three enterococcal isolates degraded gelatin. Comparing obtained results with those previously achieved in examination of LAB microflora in another Zlatar BGZLS cheese made also from raw cow's milk, it can be concluded that LAB microflora in the Zlatar BGNV cheese is less diverse.