First Record of Seven Yeast Species from Freshwater in Korea

First Record of Seven Yeast Species from Freshwater in Korea

Yoosun Oh, Wonsu Cheon, Sangkyu Park, Hye Jin Hwang, Chang Soo Lee and Hye Yeon Mun*

Fungi Research Division, NNIBR

*Email: outcastm@nnibr.re.kr

Freshwater habitats harbor a wide range of yeast species with biotechnological potential. In this study, seven yeast species not previously reported in Korea were isolated from sediment and filtered freshwater. These isolates, belonging to Ascomycota and Basidiomycota, were identified through sequence analysis of the D1/D2 domains of the 26S rDNA region. Phylogenetic analyses confirmed their taxonomic affiliations as Aureobasidium namibiae (NNIBRFG31473), Geotrichum galactomycetum (NNIBRFG3455), Peterozyma xylosa (NNIBRFG57738), Pichia fermentans (NNIBRFG52522), Apiotrichum xylopini (NNIBRFG50200), A. akiyoshidainum (NNIBRFG60728) and Sporisorium graminicola (NNIBRFG57355). To characterize their physiological properties, growth responses were evaluated across different culture media, temperature ranges, and pH levels. Morphological and physiological traits were further examined, including growth patterns, spore structure, and functional activities such as antimicrobial and enzymatic potentials. In addition, the metabolic versatility of the isolates was assessed through comprehensive carbon source utilization profiling using the Biolog FF MicroPlate™ system. These findings not only expand the knowledge of freshwater yeast diversity in Korea but also highlight their potential as valuable resources for future biotechnological applications.