Research Laboratory of Brewing Technology, Asahi Breweries Ltd, Ibaraki, Japan.
J Appl Microbiol. 2010 Dec;109(6):1906-13. doi: 10.1111/j.1365-2672.2010.04819.x.
To construct a self-cloning brewer's yeast that can minimize the unfavourable flavours caused by oxidation and certain kinds of sulfur compounds.
DNA fragments of a high-expression promoter from the TDH3 gene originating from Saccharomyces cerevisiae were integrated into the promoter regions of the S. cerevisiae-type and Saccharomyces bayanus-type SSU1 genes of bottom-fermenting brewer's yeast. PCR and sequencing confirmed the TDH3 promoter was correctly introduced into the SSU1 regions of the constructed yeasts, and no foreign DNA sequences were found. Using the constructed yeasts, the concentration of sulfite in fermenting wort was higher when compared with the parent strain. In addition, the concentrations of hydrogen sulfide, 3-methyl-2-buten-1-thiol (MBT) and 2-mercapto-3-methyl-1-butanol (2M3MB) were lower when compared with the parent strain.
We successfully constructed a self-cloning brewer's yeast with high SSU1 expression that enhanced the sulfite-excreting ability and diminished the production ability of hydrogen sulfide, MBT and 2M3MB.
The self-cloning brewer's yeast with high SSU1 expression would contribute to the production of superior quality beer with a high concentration of sulfite and low concentrations of hydrogen sulfide, MBT and 2M3MB.
构建一种自克隆啤酒酵母，最大限度地减少氧化和某些类型的硫化合物引起的不良风味。
将来自酿酒酵母的 TDH3 基因的高表达启动子的 DNA 片段整合到下面发酵啤酒酵母的酿酒酵母型和 Saccharomyces bayanus 型 SSU1 基因的启动子区域。PCR 和测序证实 TDH3 启动子已正确引入构建酵母的 SSU1 区域，未发现外源 DNA 序列。与亲本菌株相比，使用构建的酵母发酵麦汁中的亚硫酸盐浓度更高。此外，与亲本菌株相比，硫化氢、3-甲基-2-丁烯-1-硫醇 (MBT) 和 2-巯基-3-甲基-1-丁醇 (2M3MB) 的浓度更低。
我们成功构建了一种高 SSU1 表达的自克隆啤酒酵母，增强了亚硫酸盐的排泄能力，降低了硫化氢、MBT 和 2M3MB 的产生能力。
高 SSU1 表达的自克隆啤酒酵母将有助于生产高浓度亚硫酸盐、低浓度硫化氢、MBT 和 2M3MB 的优质啤酒。
