title: Formation of Guaiacol by Spoilage Bacteria from Vanillic Acid, a Product of Rice Koji Cultivation, in Japanese Sake Brewing.
abstract: The formation of guaiacol, a potent phenolic off-odor compound in the Japanese sake brewing process, was investigated. Eight rice koji samples were analyzed, and one contained guaiacol and 4-vinylguaiacol (4-VG) at extraordinarily high levels: 374 and 2433 μg/kg dry mass koji, respectively. All samples contained ferulic and vanillic acids at concentrations of mg/kg dry mass koji. Guaiacol forming microorganisms were isolated from four rice koji samples. They were identified as Bacillus subtilis, B. amyloliquefaciens/subtilis, and Staphylococcus gallinarum using 16S rRNA gene sequence. These spoilage bacteria convert vanillic acid to guaiacol and ferulic acid to 4-VG. However, they convert very little ferulic acid or 4-VG to guaiacol. Nine strains of koji fungi tested produced vanillic acid at the mg/kg dry mass koji level after cultivation. These results indicated that spoilage bacteria form guaiacol from vanillic acid, which is a product of koji cultivation in the sake brewing process.
authors.affiliation: Department of Biological Resource Sciences, Akita Prefectural University , Nakano Shimoshinjo, Akita 010-0195, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ito
authors.affiliation: Department of Biological Resource Sciences, Akita Prefectural University , Nakano Shimoshinjo, Akita 010-0195, Japan.
authors.forename: Mahito
authors.initials: M
authors.lastname: Konno
authors.affiliation: Department of Biological Resource Sciences, Akita Prefectural University , Nakano Shimoshinjo, Akita 010-0195, Japan.
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Shimura
authors.affiliation: Akita Research Institute for Food & Brewing , 4-26 Sanuki, Araya-machi, Akita 010-1623, Japan.
authors.forename: Seiei
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: Akita Research Institute for Food & Brewing , 4-26 Sanuki, Araya-machi, Akita 010-1623, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: Department of Biological Resource Sciences, Akita Prefectural University , Nakano Shimoshinjo, Akita 010-0195, Japan.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Hashizume
mesh_terms: D000069977:Bacillus amyloliquefaciens / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001412:Bacillus subtilis / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D003373:Coumaric Acids / Q000032:analysis / Q000378:metabolism; D005506:Food Contamination / Q000032:analysis; D006139:Guaiacol / Q000032:analysis / Q000378:metabolism*; D012275:Oryza / Q000378:metabolism / Q000382:microbiology*; D013210:Staphylococcus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D014641:Vanillic Acid / Q000032:analysis / Q000378:metabolism*; D014920:Wine / Q000032:analysis* / Q000382:microbiology
chemical_list: D003373:Coumaric Acids; D006139:Guaiacol; C004999:ferulic acid; D014641:Vanillic Acid
keywords: guaiacol; koji; sake brewing; spoilage bacteria; vanillic acid