title: Defective quiescence entry promotes the fermentation performance of bottom-fermenting brewer's yeast.
abstract: One of the key processes in making beer is fermentation. In the fermentation process, brewer's yeast plays an essential role in both the production of ethanol and the flavor profile of beer. Therefore, the mechanism of ethanol fermentation by of brewer's yeast is attracting much attention. The high ethanol productivity of sake yeast has provided a good basis from which to investigate the factors that regulate the fermentation rates of brewer's yeast. Recent studies found that the elevated fermentation rate of sake Saccharomyces cerevisiae species is closely related to a defective transition from vegetative growth to the quiescent (G0) state. In the present study, to clarify the relationship between the fermentation rate of brewer's yeast and entry into G0, we constructed two types of mutant of the bottom-fermenting brewer's yeast Saccharomyces pastorianus Weihenstephan 34/70: a RIM15 gene disruptant that was defective in entry into G0; and a CLN3ΔPEST mutant, in which the G1cyclin Cln3p accumulated at high levels. Both strains exhibited higher fermentation rates under high-maltose medium or high-gravity wort conditions (20° Plato) as compared with the wild-type strain. Furthermore, G1arrest and/or G0entry were defective in both the RIM15 disruptant and the CLN3ΔPEST mutant as compared with the wild-type strain. Taken together, these results indicate that regulation of the G0/G1transition might govern the fermentation rate of bottom-fermenting brewer's yeast in high-gravity wort.
authors.affiliation: Department of Brewing Microbiology, Asahi Breweries Ltd., 1-1-21 Midori, Moriya, Ibaraki 302-0106, Japan. Electronic address: mayu.oomuro@asahibeer.co.jp.
authors.forename: Mayu
authors.initials: M
authors.lastname: Oomuro
authors.affiliation: Department of Brewing Microbiology, Asahi Breweries Ltd., 1-1-21 Midori, Moriya, Ibaraki 302-0106, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Kato
authors.affiliation: National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-0046, Japan.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-0046, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Watanabe
authors.affiliation: Department of Brewing Microbiology, Asahi Breweries Ltd., 1-1-21 Midori, Moriya, Ibaraki 302-0106, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Motoyama
authors.affiliation: Quality Control Center, Asahi Breweries Ltd., 1-1-21 Midori, Moriya, Ibaraki 302-0106, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Yamagishi
authors.affiliation: National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-0046, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Akao
authors.affiliation: Department of Brewing Microbiology, Asahi Breweries Ltd., 1-1-21 Midori, Moriya, Ibaraki 302-0106, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Aizawa
mesh_terms: D000434:Alcoholic Beverages; D001515:Beer; D019149:Bioreactors / Q000382:microbiology; D016213:Cyclins / Q000235:genetics* / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000235:genetics*; D005421:Flavoring Agents / Q000378:metabolism; D018471:Hypergravity; D008320:Maltose; D030781:Organisms, Genetically Modified; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D016192:Resting Phase, Cell Cycle / Q000235:genetics*; D012440:Saccharomyces / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: C079895:CLN3 protein, S cerevisiae; D016213:Cyclins; D005421:Flavoring Agents; D029701:Saccharomyces cerevisiae Proteins; D000431:Ethanol; D008320:Maltose; D011494:Protein Kinases; C410736:Rim15 protein, S cerevisiae
keywords: Brewer's yeast; CLN3; Ethanol fermentation; G(0) entry; Quiescent state; RIM15; Saccharomyces pastorianus