Bioraznolikost mikrobnih konzorcija izoliranih iz tradicionalnog svježeg ovčjeg sira Karakačanski skakutanac

The aim of this study was to assess the structure of indigenous microbial community associated with traditional fresh sheep cheese Karakačanski skakutanac and to preserve autochthonous microbial consortia. Eleven cheeses were sampled during production season (April-September) and subjected to microbiological analysis. Bacterial DNA was isolated by Maxwell®16 DNA system from 99 microbial consortia harvested from three culture media (M17, Rogosa, CATC) on the 1st, 2nd and 3rd day of the cheese shelf life. The extracted bulk DNA (n = 99) was used as a template for PCR-ARDRA and PCR-DGGE analysis. There were no dramatic shifts in the bacterial number and structure of the microbial consortia harvested on the 1st, 2nd or 3rd day of the cheese shelf life neither during period of sampling. Lactococcus lactis subsp. lactis reached the number of 107-108 CFU g-1, while Leuconostoc pseudomesenteroides, Enterococcus faecalis, and Lactobacillus versmoldensis were identified only at lower dilutions (10-2 - 10-3). This first polyphasic microbiological-molecular study of the Karakačanski skakutanac indicated the main LAB representatives associated with the cheese. Obtained autochthonous microbial consortia present a valuable pool of strains for further genetic and functional characterizations.Cilj ovog rada bio je analizirati strukturu mikrobnih konzorcija tradicionalnog svježeg ovčjeg sira Karakačanski skakutanac. Jedanaest sireva sakupljeno je tijekom sezone proizvodnje od travnja do rujna. Mikrobni konzorciji sakupljeni su sa 3 hranjive podloge (M17, Rogosa, CATC) od 11 sireva nakon prvog, drugog, i trećeg dana proizvodnje. Mikrobna DNA je izolirana iz 99 konzorcija, te korištena u PCR-ARDRA i PCR-DGGE analizi. Nije bilo promjene u strukturi mikrobnih konzorcija sakupljenih prvog, drugog i trećeg dana nakon proizvodnje, niti tijekom sezone. Utvrđena je dominantnost populacije Lactococcus lactis subsp. lactis (107-108 CFU g-1), dok su ostale vrste bakterija mliječne kiseline, Leuconostoc pseudomesenteroides, Enterococcus faecalis i Lactobacillus versmoldensis, identificirane samo na nižim razrjeđenjima (10-2-10-3). Ova prva mikrobiološko- molekularna analiza tradicionalnog sira Karakačanski skakutanac omogućila je uvid u strukturu njegove specifične mikrobne populacije. Sakupljeni mikrobni konzorciji predstavljaju značajan izvor sojeva za daljnju genetsku i funkcionalnu karakterizaciju