title: Pyruvate decarboxylase encoded by the PDC1 gene contributes, at least partially, to the decarboxylation of alpha-ketoisocaproate for isoamyl alcohol formation in Saccharomyces cerevisiae.
abstract: Isoamyl alcohol is an important flavor component of yeast-fermented alcoholic beverages. To identify the enzyme and gene involved in the decarboxylation of alpha-ketoisocaproate (alpha-KIC) for isoamyl alcohol formation, the enzyme was partially purified and analyzed by mass spectrometry. The pyruvate decarboxylase encoded by the PDC1 gene was considered a likely candidate enzyme. Genetic analysis showed that the activity of alpha-KIC decarboxylase and production of isoamyl alcohol partially decreased in a pdc1 null mutant and increased in a transformant with a multi-copy plasmid carrying the PDC1 gene. These results indicate that pyruvate decarboxylase encoded by the PDC1 gene contributes, at least partially, to the decarboxylation of alpha-KIC for isoamyl alcohol formation.
authors.affiliation: Central Laboratories for Key Technology, Kirin Brewery Co. Ltd., 1-13-5 Fukuura, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan. hyoshimoto@kirin.co.jp
authors.forename: H
authors.initials: H
authors.lastname: Yoshimoto
authors.forename: T
authors.initials: T
authors.lastname: Fukushige
authors.forename: T
authors.initials: T
authors.lastname: Yonezawa
authors.forename: Y
authors.initials: Y
authors.lastname: Sakai
authors.forename: K
authors.initials: K
authors.lastname: Okawa
authors.forename: A
authors.initials: A
authors.lastname: Iwamatsu
authors.forename: H
authors.initials: H
authors.lastname: Sone
authors.forename: Y
authors.initials: Y
authors.lastname: Tamai