WIN AUNG, YUKA WATANABE AND FUMIO HASHINAGA
Abstract
Of 73 yeast strains isolated from indigenous alcohol starters of Nepal, Myanmar, Cambodia and Indonesia, 7 strains that grew and fermented at above 42°C were selected. Fermentation was carried out in medium containing 15% (w/v) glucose at 40°C using the selected yeast strains, and the ethanol productivities were measured after 48 h incubation. Two strains, MN1-3 and CS2-3 were found to be higher ethanol productivity of 6.2 and 6.7% (w/v), respectively. Thermotolerant, fermentative yeast strains were identified by conventional and molecular techniques. In the molecular technique, polymerase chain reaction (PCR) amplified 18S rDNA and internal transcribed spacer 1 (ITS1) genes using specific primers were analyzed. As a result, the strains selected were identified as follows: NP3-2 and MN1-5, Issatchenkia orientalis; MN1-3 and CS2-3, Saccharomyces cerevisiae; CS1-1, Pichia fabianii; RA2-1, Clavispora lusitaniae and RA3-3, Candida glabrata.