Superior molasses assimilation, stress tolerance, and trehalose accumulation of Baker's yeast isolated from dried sweet potatoes (hoshi-imo)

• Published in: Bioscience, biotechnology, and biochemistry Vol. 68; no. 7; pp. 1442 - 1448
• Main Authors: Nishida, O. (National Food Research Inst., Tsukuba, Ibaraki (Japan)), Kuwazaki, S, Suzuki, C, Shima, J
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Society for Bioscience, Biotechnology, and Agrochemistry 01.07.2004; Japan Society for Bioscience Biotechnology and Agrochemistry; Oxford University Press
• Subjects: baker's yeast; BAKERS' YEAST; Biological and medical sciences; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; ELECTROPHORESIS; Electrophoresis, Gel, Pulsed-Field; Fermentation; Food Microbiology; Food Preservation; freeze tolerance; FREEZING; Fundamental and applied biological sciences. Psychology; Ipomoea batatas - microbiology; ISOLATION; Karyotyping; MOLASSES; osmotolerance; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - isolation & purification; Saccharomyces cerevisiae - metabolism; Solanum tuberosum; STRESS; SWEET POTATOES; TOLERANCE; TREHALOSE; Trehalose - metabolism; trehalose accumulation; Assimilation; Molasses; Trehalose; Tolerance; Convolvulaceae; Accumulation; Stress; freeze tolerance; osmotolerance; baker's yeast; Dicotyledones; Angiospermae; trehalose accumulation; Spermatophyta; Baker yeast; Ipomoea batatas; Freeze
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.68.1442

Yeast strains were isolated from dried sweet potatoes (hoshi-imo), a traditional preserved food in Japan. Dough fermentation ability, freeze tolerance, and growth rates in molasses, which are important characteristics of commercial baker's yeast, were compared between these yeast strains and a commercial yeast derivative that had typical characteristics of commercial strains. Classification tests including pulse-field gel electrophoresis and fermentation/assimilation ability of sugars showed that almost the stains isolated belonged to Saccharomyces cerevisiae. One strain. ONY1, accumulated intracellular trehalose at a higher level than commercial strain T128. Correlated with intracellular trehalose contents, the fermentation ability of high-sugar dough containing ONY1 was higher. ONY1 also showed higher freeze tolerance in both low-sugar and high-sugar doughs. The growth rate of ONY1 was significantly higher under batch and fedbatch cultivation conditions using either molasses or synthetic medium than that of strain T128. These results suggest that ONY1 has potential commercial use as baker's yeast for frozen dough and high-sugar dough.