title: Glucosylceramide Contained in Koji Mold-Cultured Cereal Confers Membrane and Flavor Modification and Stress Tolerance to Saccharomyces cerevisiae during Coculture Fermentation.
abstract: In nature, different microorganisms create communities through their physiochemical and metabolic interactions. Many fermenting microbes, such as yeasts, lactic acid bacteria, and acetic acid bacteria, secrete acidic substances and grow faster at acidic pH values. However, on the surface of cereals, the pH is neutral to alkaline. Therefore, in order to grow on cereals, microbes must adapt to the alkaline environment at the initial stage of colonization; such adaptations are also crucial for industrial fermentation. Here, we show that the yeast Saccharomyces cerevisiae, which is incapable of synthesizing glucosylceramide (GlcCer), adapted to alkaline conditions after exposure to GlcCer from koji cereal cultured with Aspergillus kawachii. We also show that various species of GlcCer derived from different plants and fungi similarly conferred alkali tolerance to yeast. Although exogenous ceramide also enhanced the alkali tolerance of yeast, no discernible degradation of GlcCer to ceramide was observed in the yeast culture, suggesting that exogenous GlcCer itself exerted the activity. Exogenous GlcCer also increased ethanol tolerance and modified the flavor profile of the yeast cells by altering the membrane properties. These results indicate that GlcCer from A. kawachii modifies the physiology of the yeast S. cerevisiae and demonstrate a new mechanism for cooperation between microbes in food fermentation.
authors: Department of Biochemistry and Applied Biosciences, United Graduate School of Agricultural Sciences, Kagoshima University, Korimoto, Kagoshima, Japan Department of Environmental Science, Faculty of Agriculture, Saga University, Saga City, Saga, Japan Industrial Technology Center of Saga Prefecture, Saga City, Saga, Japan.
authors: Kazutaka
authors: K
authors: Sawada
authors: Department of Environmental Science, Faculty of Agriculture, Saga University, Saga City, Saga, Japan.
authors: Tomoya
authors: T
authors: Sato
authors: Department of Environmental Science, Faculty of Agriculture, Saga University, Saga City, Saga, Japan.
authors: Hiroshi
authors: H
authors: Hamajima
authors: Department of Biochemistry and Applied Biosciences, United Graduate School of Agricultural Sciences, Kagoshima University, Korimoto, Kagoshima, Japan Department of Environmental Science, Faculty of Agriculture, Saga University, Saga City, Saga, Japan.
authors: Lahiru Niroshan
authors: LN
authors: Jayakody
authors: Department of Environmental Science, Faculty of Agriculture, Saga University, Saga City, Saga, Japan.
authors: Miyo
authors: M
authors: Hirata
authors: Department of Environmental Science, Faculty of Agriculture, Saga University, Saga City, Saga, Japan.
authors: Mikako
authors: M
authors: Yamashiro
authors: Department of Environmental Science, Faculty of Agriculture, Saga University, Saga City, Saga, Japan.
authors: Marie
authors: M
authors: Tajima
authors: Department of Applied Biochemistry and Food Science, Faculty of Agriculture, Saga University, Saga City, Saga, Japan.
authors: Susumu
authors: S
authors: Mitsutake
authors: Department of Biochemistry and Applied Biosciences, United Graduate School of Agricultural Sciences, Kagoshima University, Korimoto, Kagoshima, Japan Department of Applied Biochemistry and Food Science, Faculty of Agriculture, Saga University, Saga City, Saga, Japan.
authors: Koji
authors: K
authors: Nagao
authors: Industrial Technology Center of Saga Prefecture, Saga City, Saga, Japan.
authors: Keisuke
authors: K
authors: Tsuge
authors: Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, Kanagawa, Japan.
authors: Fumiyoshi
authors: F
authors: Abe
authors: Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo, Japan.
authors: Kentaro
authors: K
authors: Hanada
authors: Department of Biochemistry and Applied Biosciences, United Graduate School of Agricultural Sciences, Kagoshima University, Korimoto, Kagoshima, Japan Department of Environmental Science, Faculty of Agriculture, Saga University, Saga City, Saga, Japan ktgkhrs@cc.saga-u.ac.jp.
authors: Hiroshi
authors: H
authors: Kitagaki
mesh_terms: D001230:Aspergillus / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D002523:Edible Grain / Q000378:metabolism / Q000382:microbiology*; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D005421:Flavoring Agents / Q000378:metabolism*; D005963:Glucosylceramides / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008566:Membranes / Q000187:drug effects*; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D013312:Stress, Physiological / Q000187:drug effects*
chemical_list: D005421:Flavoring Agents; D005963:Glucosylceramides; D000431:Ethanol