Investigation of some biochemical properties, antimicrobial activity and antibiotic resistances of kefir supernatants and lactococcus lactis ssp. lactis strains isolated from raw cow milk and cheese samples
2018
Shila VAHABZADEH | Haydar ÖZPINAR
In this study some biochemical characteristics, antibiotic resistance profiles and antibacterial activity of kefir microfloras (kefir supernatants) and Lactococcus lactis ssp. lactis (L. lactis ssp. lactis) bacteria isolated from cheese made from sheep milk and raw cow milk were investigated. In this study, 30 kefir supernatants and 60 isolates of L. lactis ssp. lactis were analyzed. 30 isolates obtained from raw cow milk and 30 isolates obtained from raw sheep cheeses. In kefir supernatants the highest antimicrobial activity was observed against B. cereus, followed by E. coli, S. aureus whereas no antimicrobial activity was observed against the E. faecalis. Kefir supernatants exhibited highest resistance to chloramphenicol and lowest resistance to erythromycin. The highest antimicrobial activity in L. lactis ssp. lactis isolates obtained from raw sheep cheese and raw cow milk samples were found against E. faecalis followed by S. aureus, L. sakei and E. coli respectively. The isolates obtained from raw sheep cheese samples 43.3% were resistant to streptomycin, 13.3% tetracycline and 22.2% erythromycin. The isolates obtained from raw cow milk samples 40% were resistant to streptomycin, 40% tetracycline, 16.7% ampicillin and 23.3% erythromycin. The results showed that L. lactis ssp. lactis bacteria isolated from cheese samples derived from raw sheep milk demonstrated better antimicrobial activity and lactic acid production. Among all isolates obtained from raw cow milks and raw sheep cheeses Tet(S) resistance gene was confirmed in 7 (11.7%), Str(A) in 6 (10%) and Str(B) in 1 (1.7%) isolates by PCR method.
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