Rainieri Sandra, Kodama Yukiko, Nakao Yoshihiro, Pulvirenti Andrea, Giudici Paolo
Department of Agricultural and Food Sciences, University of Modena and Reggio Emilia, Reggio Emilia, Italy.
FEMS Yeast Res. 2008 Jun;8(4):586-96. doi: 10.1111/j.1567-1364.2008.00363.x. Epub 2008 Mar 3.
In this work, we compared the mtDNA of a number of interspecific Saccharomyces hybrids (Saccharomyces cerevisiae x Saccharomyces uvarum and S. cerevisiae x Saccharomyces bayanus) to the mtDNA of 22 lager brewing strains that are thought to be the result of a natural hybridization between S. cerevisiae and another Saccharomyces yeast, possibly belonging to the species S. bayanus. We detected that in hybrids constructed in vitro, the mtDNA could be inherited from either parental strain. Conversely, in the lager strains tested, the mtDNA was never of the S. cerevisiae type. Moreover, the nucleotide sequence of lager brewing strains COXII gene was identical to S. bayanus strain NBRC 1948 COXII gene. MtDNA restriction analysis carried out with three enzymes confirmed this finding. However, restriction analysis with a fourth enzyme (AvaI) provided restriction patterns for lager strains that differed from those of S. bayanus strain NBRC 1948. Our results raise the hypothesis that the human-driven selection carried out on existing lager yeasts has favored only those bearing optimal fermentation characteristics at low temperatures, which harbor the mtDNA of S. bayanus.
在这项研究中，我们将一些种间酿酒酵母杂种（酿酒酵母×葡萄汁酵母以及酿酒酵母×贝酵母）的线粒体DNA（mtDNA）与22种拉格啤酒酿造菌株的mtDNA进行了比较，这些拉格啤酒酿造菌株被认为是酿酒酵母与另一种可能属于贝酵母的酿酒酵母自然杂交的结果。我们检测到，在体外构建的杂种中，mtDNA可以从任一亲本菌株遗传而来。相反，在测试的拉格啤酒菌株中，mtDNA从未是酿酒酵母类型。此外，拉格啤酒酿造菌株COXII基因的核苷酸序列与贝酵母菌株NBRC 1948的COXII基因相同。用三种酶进行的mtDNA限制性分析证实了这一发现。然而，用第四种酶（AvaI）进行的限制性分析提供的拉格啤酒菌株的限制性图谱与贝酵母菌株NBRC 1948的不同。我们的结果提出了一个假说，即对现有拉格啤酒酵母进行的人为驱动选择仅有利于那些在低温下具有最佳发酵特性且含有贝酵母mtDNA的酵母。
