Isolation and molecular identification of yeast cells and their evaluation for producing yeast extract and beta glucan

Yeast is a unicellular fungus with thick cell wall and nucleus. Nowadays this microorganism considered as important fungi in commercial industry because of their products specially yeast extract and beta glucan. The purpose of this study was isolation and identification and screening of yeast cells for production of beta glucan and yeast cells. Yeast cells were isolated from plant and dairy samples and destruction of their cell walls was carried out using acidic condition, kiwi extract and change of osmotic pressure methods. In addition, isolation, purification and verification of beta glucan were done by modified Acid/Alkaline and Callose and Proton nuclear magnetic (H1NMR) methods respectively. The results obtained indicated that yeast cells were isolated from all samples. Two yeast cells based on their sizes and potential of growth were selected for further study. 18SrDNA gene sequencing of isolated strains identified them as Kluyveromyces marxianus and Saccharomyces cerevisiae. Our finding indicated that kiwi extract and change of osmotic pressure were favorable methods (p≤0.05) for production of yeast extract. Furthermore the results of Callose and H1NMR methods verified the production and purification of beta glucan. Hence based on our results production of beta glucan in industry scales is possible in our country Iran.