Title Degradation of Malic Acid by Issatchenkia orientalis KMBL 5774, an Acidophilic Yeast Strain Isolated from Korean Grape Wine Pomace
Author Sung-Hee Seo, Chang-Ho Rhee, and Heui-Dong Park*
Address Department of Life and Food Sciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 702-701, Republic of Korea
Bibliography Journal of Microbiology, 45(6),521-527, 2007,
DOI
Key Words acidophilic yeast, grape, malic acid degradation, Issatchenkia orientalis
Abstract Several yeast strains degrading malic acid as a sole carbon and energy source were isolated from Korean wine pomace after enrichment culture in the presence of malic acid. Among them, the strain designated as KMBL 5774 showed the highest malic acid degrading ability. It was identified as Issatchenkia orientalis based on its morphological and physiological characteristics as well as the nucleotide sequences of the internal transcribed spacer (ITS) I-5.8S rDNA-ITS II region. Phylogenetic analysis of the ITS I-5.8S rDNAITS II sequences showed that the KMBL 5774 is the closest to I. orientalis zhuan 192. Identity of the sequences of the KMBL 5774 was 99.5% with those of I. orientalis zhuan 192. The optimal pH of the media for the growth and malic acid degradation by the yeast was between 2.0 and 3.0, suggesting that the strain is an acidophile. Under the optimized conditions, the yeast could degrade 95.5% of the malic acid after 24 h of incubation at 30°C in YNB media containing 2% malic acid as a sole carbon and energy source.
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