Culture-dependent molecular identification of atypical bacteria in traditionally produced yogurt from Kars, Türkiye

The study reported the isolation of culturable bacteria from different homemade yogurt samples traditionally known to be produced in the vicinity of Kars province in Türkiye. The study described several techniques of analysis for nutritional, physicochemical, and microbiological characters, and the microorganisms were characterized by morphological criteria and 16S rRNA gene sequence analysis. According to the sequencing results, the isolates were similar to members of the genus Bacillus, including Bacillus aerius 24Kᵀ, Bacillus amyloliquefaciens DSM 7ᵀ, Bacillus cereus ATCC 14579ᵀ, Bacillus halotolerans LMG 24826ᵀ, Bacillus subtilis DSM 10ᵀ, Bacillus simplex DSM 1321ᵀ, Bacillus tequilensis KCTC 13622ᵀ, and Bacillus wiedmannii FSL W8-0169ᵀ. Other genera detected included Staphylococcus epidermidis ATCC 12228ᵀ, Klebsiella oxytoca ATCC 13182ᵀ, Ralstonia pickettii ATCC 27511ᵀ, and Pseudomonas helleri DSM 26263ᵀ (LPSN, accessed 12 October 2025). P. helleri was detected in a traditional yogurt sample from among the identified isolates, ensuring that there were bacteria not commonly thought to be part of yogurt fermentation. Physicochemical analyses revealed pH values ranging from 2.97-4.89, titration acidity 1.22-1.58%, serum separation 10.00-52.00 ml/100g, dry matter 11.84-16.33%, fat 2.43-3.87%, non-fat dry matter 8.33-13.22% and ash content 0.61-1.03%. In conclusion, the findings indicate that there is a wide variance in the hygienic and microbiological quality of home-processed yogurt and that hygienic practices and monitoring are extremely important in home processing systems.