Screening and Characterization of Amylolytic Basidiomycetes Yeasts

Abstract

　In this study, we screened six yeast strains from natural environments in Gifu Prefecture, Japan, as potential amylolytic yeasts. All strains showed amylolytic activities on amylose plates and exhibited amylase activities. Strains GY16 and GY73 were genetically identified as Saitozyma flava (syn. Cryptococcus flavus) and Ustilago sp., respectively, while the other four strains were identified as Papiliotrema laurentii. Strains GY16 and GY73 each showed a single active band for amylase on native-PAGE. The optimum temperature for extracellular amylase activity was 55℃ and 60℃ in strains GY16 and GY73, respectively, and the optimum pH was 5.0 and 5.5, respectively. Moreover, the partial AMY1 gene was identified on the genome of strain GY16. These findings indicate that the isolated amylolytic yeast strains have potential as producers for novel types of amylases that are useful in the food industry.