啤酒酵母和糖化酵母的杂交

本文进行了生产用啤酒酵母07和糖化酵母Saccharomyoes diastat(?)cus 1752的种间杂交,试图通过杂交的方法将糖化酵母的DEX基因重组入杂交子中并得以表达。实验表明,杂交子不仅能够水解和发酵糊精即获得并表达了DEX基因,而且在细胞形态、巨大菌落形态、DNA含量以及产孢能力等方面均不同于单倍体双亲株1303 a his dex和2002 a ade DEX。遗传分析表明,杂交种N3204的51个减数分裂产物其糊精发酵特性以及遗传标记均出现了双亲类型的分离或重组现象。这些结果都证明,通过传统的杂交方法可以获得啤酒酵母和糖化酵母的杂交种。与生产用啤酒酵母亲株07比较,杂交种N3204和N3216在IL啤酒发酵过程中显示酒精产生速率快,发酵度高等较优良的发酵特性。

Hybridization of a Brewing Yeast with a Yeast Strain of Saccharomyces diastaticus

In this paper, the brewing yeast strain 07 was crossed with the strain 1752 of Saccharomyces diastaticus with the DEX gene transfered to and expressed in the hybrides so constructed. It was demonstrated that such hybrids not only obtained the DEX gene from the strain 1752, capable of hydrolyzing and fermenting dextrin, but also differed greatly from their parental haploids 1303 a his dex and 2002a ade DEX in many aspects including cell morphology, giant colony morphology, DNA content per cell, and the ability to sporulate.Genetic analysis showed that among 51 meiosis products isolated from a hybrid strain N3204 by mass spore isolation, the segregation and recombination of DEX gene and genetic markers had appeared. These findings have come to the conclusion that true and stable hybrids between brewing yeasts and yeasts of S. diastaticus were able to be successfully constructed by the conventional hybridisation method. As compared with the brewing yeast 07, the hybrid strains N3204 and N3216 exhibited increased attenuation rates and possessed the ability to supe-rattenuate the wort in 11.5° P. on 2-L scale fermentation.