Isolation and characterization of Saccharomyces cerevisiae from Izu-Akazawa deep seawater

Abstract

Deep seawater (DSW) is widely used in various fields today. In recent studies, specific microbial communities in DSW have been reported, though there are fewer number of living microorganisms. The purpose of this study was to isolate Saccharomyces cerevisiae from DSW because this species has been widely used in the food and cosmetics fields. The bag filters used for filtration in the DSW pumping facility were prepared as isolation sources and 75 yeast strains were isolated in total. As a result of analyzing the sequence of the 26S rRNA gene, the isolated strains were classified into 13 genera 21 species of yeast, and 3 strains of them were S. cerevisiae (strains SCAK-1, 2and 3). As a result of comparing the characteristics of strains SCAK-1, 2 and 3 with strain NRIC-1560, which is the type strain of S. cerevisiae, they were able to grow at a lower temperature and were much more highly resistant to NaCl concentration and water pressure. In addition, strains SCAK-1 and 2 indicated unique characteristics such as longer chronological lifespan and higher oxidative stress tolerance.