沙棘果酒专用酵母菌的分子生物学鉴定及其应用研究

Molecular Biological Identification and Application of Yeast Strain for Fermentation of Sea-buckthorn Wine

目前工业上尚无酿造沙棘果酒的专用酵母菌,因此,筛选出适合酿造沙棘果酒的优良酵母菌尤为必要。利用ITS1-5.8S-ITS2 rDNA序列分析及构建系统发育树对自选酵母菌Y23进行分子生物学鉴定。结果表明,克隆的自选酵母菌Y23的5.8S-ITS rDNA序列(GenBank接受号:FJ793809)全长874bp。自选酵母菌Y23与Saccharomyces cerevisiae CB S423T(AM262829)的遗传距离最近,两者之间的同源性为100%,因此,鉴定酵母菌Y23为酵母属(Sacchar omyces)酿酒酵母(Sacchar omyces cerevisiae)。通过响应面分析法研究初始糖度、发酵温度、接种量对自选酵母菌Y23酿造沙棘果酒品质的影响,得出沙棘果酒质量与影响因素间的回归模型,并根据模型进行工艺参数优化。结果表明,接种量对沙棘果酒质量的影响极显著(P<0.01)。利用自选酵母菌Y23酿造沙棘果酒的最佳工艺参数是:初始糖度19.9%、发酵温度25.4℃、接种量10.3%。

Currently,a special yeast strain for industrial fermentation of sea-buckthorn wine has highly required and it is necessary to screen a fine yeast strain suitable for the fermentation of sea-buckthorn wine.A yeast Y23 was identified by ITS15.8S-ITS2 rDNA sequence analysis and phylogenetic dendrogram construction.Results showed that the complete sequence of 5.8S-ITS rDNA（GenBank Accession：FJ793809） was 874 bp.The yeast Y23 had the nearest heredity with Saccharomyces cerevisiae CBS423T（AM262829）,and the homology of their gene sequences were up to 100% so that the selected yeast Y23 was identified as Saccharomyces cerevisiae belonging to the family of Saccharomyces.The yeast Y23 was used as experimental strain to evaluate the effects of initial sugar degree,fermentation temperature and inoculum amount on the quality of sea-buckthorn wine by response surface methodology（RSM）.A regression equation with high reliability was obtained and the above technological parameters were optimized using this equation model.Inoculum amount revealed a significant effect on the quality of seabuckthorn wine（P〈0.01）.The optimal values of technological parameters for improved quality of sea-buckthorn wine were as follows：original sugar degree 19.9%,fermentation temperature 25.4 ℃ and inoculum amount 10.3%.