title: Bioconversion of ferulic acid to 4-vinylguaiacol and 4-ethylguaiacol and of 4-vinylguaiacol to 4-ethylguaiacol by halotolerant yeasts belonging to the genus Candida.
abstract: In order to examine the genesis of the characteristic flavors of soy sauce and miso, seven novel halotolerant yeast strains of two types, which showed convertibility of ferulic acid (FA) to 4-vinylguaiacol (4-VG) and to 4-ethylguaiacol (4-EG), were isolated from miso-koji and miso pastes. Two of these strains were identified as Candida guilliermondii (anamorph of Pichia guilliermondii), and Candida fermentati (anamorph of Pichia caribbica), based on sequence analyses of a partial 26S ribosomal RNA gene and the region of internal transcribed spacers 1 and 2, and the 5.8S ribosomal RNA gene. Moreover, we also found three Candida etchellsii strains which showed convertibility of FA to 4-VG, but not to 4-EG, and two atypical strains of Candida versatilis which showed no convertibility of FA to 4-VG, but did show convertibility of 4-VG to 4-EG from soy sauce mashes. The bioconversion pathway from FA to 4-EG via 4-VG in halotolerant yeasts and bacteria is discussed.
authors.affiliation: Fermentation and Food Research Branch, Kagawa Prefectural Industrial Center, Kagawa, Japan. js3501@pref.kagawa.lg.jp
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Suezawa
authors.forename: Motofumi
authors.initials: M
authors.lastname: Suzuki
mesh_terms: D002175:Candida / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003373:Coumaric Acids / Q000378:metabolism*; D003470:Culture Media; D005285:Fermentation / Q000502:physiology; D006139:Guaiacol / Q000031:analogs & derivatives* / Q000378:metabolism; D006219:Halogens / Q000494:pharmacology; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012335:RNA, Ribosomal / Q000235:genetics / Q000378:metabolism; D045730:Soy Foods / Q000032:analysis
chemical_list: D003373:Coumaric Acids; D003470:Culture Media; D006219:Halogens; D012331:RNA, Fungal; D012335:RNA, Ribosomal; C065096:RNA, ribosomal, 26S; D006139:Guaiacol; C014245:4-vinylguaiacol; C004999:ferulic acid; C084991:4-ethylguaiacol