Identification and characterization of Lactococcus starter strains in milk-based traditional fermented products in the region of Iran

摘要

The aim of the present research was identification and investigation of technological attributes of Lactococcus starter strains from traditional dairy products collected from the countryside of Boroujerd in Iran. 33 samples were cultured on selective media M17 and typical colonies surveyed for morphological properties. Totally, 37 strains were isolated based on the diversity in cell morphology and identified using API galleries and carbohydrate fermentation includes 17 strains of Lactococcus lactis (45.96%), 12 strains of Lactococcus garvieae (32.43%) and 8 strains of Lactococcusplantarum (21.62%). Strains were appraised for hydrolysis of L-arginine, casein and starch. Furthermore, strains were evaluated for the ability to grow at temperature 10 °C, 45 °C and presence of 4% and 6.5% NaCl, antibiotic sensitivity, acidification ability, proteolytic and lipolytic activities. Generally, 3 strains of Lc.garvieae (GYLC1, BWLC1, DCLC1) and 7 strains of Lc. lactis (GCLC4, GWLC2, GWLC3, SWLC1, SWLC3, BCLC5, DYLC1) exposed the highest levels of technological properties in order to use as starter cultures.