优良酿酒酵母(面包酵母)三倍体菌株的选育

通过初筛、单倍体分离、诱变、原生质体融合及杂交等育种技术选育出一株具有高生物量、耐高糖、强絮凝性能的优良酿酒酵母(面包酵母)三倍体菌株ZLFH-121,其生物量分别为原始亲株BL68、BL92、L77的1.22、1.33与1.83倍;絮凝性能明显优于原始亲株BL68、BL92.并对其培养条件进行了优化研究,结果表明三倍体菌株ZLFH-121能够很好地利用糖蜜培养基,并表现出良好的絮凝能力.在优化的培养条件下,生物量提高至93.82g/L(湿重),为初始培养条件下的1.30倍.经遗传稳定性分析,证明三倍体菌株ZLFH-121遗传稳定,是一株具有潜在应用价值的优良酿酒酵母(面包酵母)菌株.

BREEDING OF AN EXCELLENT TRIPLOID BAKER'S YEAST STRAIN

A high biomass production, high-sugar-tolerance and high flocculation triploid baker's yeast strain ZLFH-121(MATa/a/a, FLO1) was constructed by protoplast fusion combined with mass-mating. Study on the biomass production, high-sugar-tolerance and flocculation of the triploid strain ZLFH-121showed that this strain had improved qualities. The biomass of ZLFH-121 was 1.22, 1.33 and 1.83 times that of the parental strains BL68, BL92 and L77, respectively. The ability of flocculation of the hybrid strain was better than that of the parental strains BL68 and BL92.The factors that affected the biomass of ZLFH-121 were also tested. Biomass under the optimal fermentation condition showed a 1.3-fold improvement over that of the initial condition. The triploid baker's yeast strain ZLFH-121 was genetically stable as showed by analysis of genetic stability. The results indicate that the triploid strain ZLFH-121 has potential industrial value.