Comparison of culture-dependent and culture-independent techniques in the detection of lactic acid bacteria biodiversity and dynamics throughout the ripening process: The case of Turkish artisanal Tulum cheese produced in the Anamur region

Our objective was to analyze the diversity of the microbiota over 180 d of ripening of eight batches of artisanal goatskin Tulum cheeses by culture-dependent and culture-independent (PCR-DGGE) methods. V3 region of the bacterial 16S rRNA gene was amplified with the PCR after direct DNA isolation from the cheese samples. Nine different species and five genera were determined by culturing, while 11 species were identified in the PCR-DGGE technique. This diversity revealed the uniqueness of artisanal cheese varieties. The dominant genera in all the cheese samples were composed of Enterococcus species. The culture-dependent method revealed five genera (Enterococcus,Bacillus,Lactococcus,Lactobacillus, Sphingomonas) while three genera (Enterococcus, Streptococcus, Lactococcus) were detected in the culture-independent method. It was concluded that combining the two methods is important for characterizing the whole microbiota of the Tulum cheese varieties produced in the Anamur region.

KARGI TULUM PEYNİRİNİN BAZI KİMYASAL, TEKSTÜREL VE MİKROBİYOLOJİK ÖZELLİKLERİNİN BELİRLENMESİ

Kargı Tulum cheese is a type of cheese produced in the highlands in summer seasons from sheep, goat, cow and buffalo milk and their mixtures in certain proportions in the Kargı district of Çorum and put on the market in autumn. It is particularly consumed in Çorum, Kastamonu, Samsun and Ankara provinces. For the marketing of cheeses, tulums made of sheep and lamb skins are cleaned and cut into small pieces and sewn. Cheese curds, after the whey draining, are pressed into the prepared tulums by being compressed so that there is no airgap in them. Traditional production and sales methods are stil used in Kargı Tulum cheese, therefore standardized products cannot be obtained in every production. For this reason, the stages involved in the traditional cheese production and the packaging material used for ripening affect the chemical and textural properties, microbial load and therefore, quality of the product. There are few number of studies on Kargı Tulum cheese and no extensive study examined the texture and rheological characteristics of it. Cheese texture is influenced by many factors, such as composition, microbiological load, ripening conditions and proteolysis; therefore texture properties should be evaluated together with the chemical and hygenic parameters. In this study, some chemical (pH, titrationacidity, total solids, fat), textural (TPA) and microbiological characteristics (total mesophilic count, mold and yeast counts, coliform) of tulum cheese samples produced according to the tradional method with three replicates were determined. Moisture content of the Kargı Tulum cheese samples were 43.45%, fat content was found % 25.5, pH was 4.55, acidity (lacticacid %) was 2.55. According to TS 3001 Tulum Cheese Standard our Kargı Tulum cheese samples were classified as full fat cheese and our chemical composition results were in accordance with the standard. We found statistically significant differences between cheese samples for all texture parameters measured (firmness, adhessiveness, springiness, gumminess, resilience) except for chewiness. Average total mesophilic aerobic bacteria countwas 6.40 log cfu.g-1 mean mold and yeast counts were found to be 1.07 log cfu.g-1. Coliform group bacteria were not found in the analyzed samples. When microbiological results were compared statistically, it was determined that there was no significant difference between cheese samples.