Isolation Torulaspora Delbrueckii from honey associated with osmotic stress and acid production for industry application

Sugar-tolerant yeast are very important for the foods and beverage fermentation application. The purpose of this study is screening natural yeast isolates from honey samples by using molecular biological and physiology of osmoadaptation. The intergenic transcribed spacer region for sequencing of rDNA (ITS1-5.8S rDNA-ITS2) nucleotide sequence alignment method was used to identify yeast strain by PCR-amplified. Five different yeast strains were identified representing 3 different genera, Saccharomyces cerevisiae. Torulaspora delbrueckii (identity 99.76%), and Candida etchellsii (identity 99.18%) by comparison with the sequence on GenBank database (NCBI-BLAST). The occurrence of strains with special sugar tolerant with 800 g/L glucose can be beneficial for industrial fermentation. Organic acids compounds were produced by the yeast strain which were analyzed by HPLC methods. The major organic compound included citric acid (11.02 g/L), malic acid (16.62 g/L), succinic acid (4.17 g/L), formic acid (1.70 g/L) and acetic acid (6.18 g/L) were detected at 12 h, 24 h and 48 h of fermentation. The diversity of yeast species is valuable with potential for industrial applications such as in fermentation of food and beverages.