Isolation, identification and determination of Saccharomyces cerevisiae yeast species from the wines made by Spontaneous fermentation using Papazkarası grapes from Thrace region

Nowadays, especially in large-scale commercial wine production, fermentation is usually carried out by using the species of Saccharomyces cerevisiae yeast cultures. Standard wine yeast starter cultures are brought from abroad and used in industrial winemaking in our country. Thus, in course of time, the wines of all producers began to show similar characteristics. Today, studies focus on terroir wines production with local characteristics by using the countries' own local wine yeasts as a starter. Within the scope of the thesis, Papazkarası grapes were collected from 4 vineyards with different characteristics such as viticulture practices, microclimatic conditions and locations in the borders of Edirne and Kırklareli. In addition the grapes were also collected from the vineyard in Tekirdağ Viticulture Research Institute. Spontaneous fermentation was done by crushing the collected grapes. At the end of the fermentation, yeast isolations were made from the musts and a total of 66 isolates were obtained. Fermentation rate, H2S production amount, growth at high temperature, growth at high sugar concentration, resistance to high ethanol, ability to grow at low pH values, resistance to SO2, volatile acid analysis were done to determine whether they meet the technological requirements for basic winemaking, together with 1 commercial wine yeast. DNA sequencing analyzes were made by selecting 15 of those that were found to have the necessary characteristics and it was determined that they belonged to the species Saccharomyces cerevisiae. 9 different strains were detected in the DNA fingerprint analyzes performed on these isolates. Isolated yeasts are stored in glycerol stocks at -80°C in Tekirdağ Viticulture Research Institute for use in future applications.