Application of deep sea yeast-production of biosurfactants-

Abstract

Yeast is promising microbe to applying for brewing, bread-making, and some fermented foods, and to development recently for producing bio-ethanol. Yeast exists also in the deep-sea and the many species have been described from the deep-sea in previous reports. Most of the deep-sea yeasts are "non-conventional yeasts" including approximately 1000 species excepting well-known Saccharomyces cerevisiae and Schizosaccharomyces pombe, in the best of our knowledge. Yeast isolated from the deep-sea often possesses unique metabolic properties. We recently focused on a biosurfactant producing yeast, strain SY62, which was isolated from at a depth of 1,156 m in Sagami Bay in Japan. Although the yeast indicated little difference from conventional Pseudozyma hubeiensis on taxonomy, the secreted glycolipid-type biosurfactant, mannosylerythritol lipids (MEL), indicated structurally differences from those of conventional strains. The structural differences on MEL produced by SY62 resulted in the good hydrophilicity compared to those produced by conventional strains. The results indicated that the deep-sea bio-resources have great potential for exploring novel useful microorganisms and metabolites. The difference of metabolites seemed to be caused by evolution under high-pressure stress in the deep-sea.