通过原生质体融合改建酵母细胞的研究——Ⅳ.原生质体融合技术在酵母育种上的应用

HU-KDF-185菌株是通过原生质体融合并经筛选而获得的酿酒酵母(Saccharomycescerevisiae var. ellipsoideus HUK-1,(1a,his~-)与糖化酵母(Saccharomyces diastaticus, a, arg~-)的种间三倍体融合杂种.作者在实验室条件下对其发酵生物学进行比较研究后,在仙居酒厂对该融合杂种发酵不同淀粉质原料的适应性及其酒精产量作了生产规模的比较试验。结果表明,种间融合杂种HU-KDF-185对番薯渣原料的酒精产量平均为30.77％,这比我国目前广为应用的酒精生产菌株K氏酵母(29.71％)和新市一号(29.54％)分别增产3.56％和4.16％;在大米原料的发酵中,其酒精产量平均为35.38％,比大米酒精生产菌株M-85(32.87％)相对增产酒精7.64％,而番薯丝原料的酒精产量平均为30.20％,比生产菌株新市一号(28.70％)相对增产酒精5.23％.由此可见,种间融合杂种HU-KDF-185在不同类型的淀粉质原料的发酵中,其酒精增产效果显著而稳定,这也证明了我们通过原生质体融合技术所获得的种间融合杂种将是一株较优良的酒精高产菌株.同时也表明原生质体融合技术对酒精酵母的选育,特别是对那些在其生活周期中缺乏或失去有性过程的工业酵母更为有用.

The Application of Protoplast Fusion Technique to Improvement of Yeast Strain

In this paper, we present the fermentative ability of ethanol by HU-KDF-185, the interspecific fusant between Saccharomyces cerevisiae and Saccharomyces diastaticus, with different types of the starchy materials under the condition of Xian Ju distillery. The experimental results show that the average ethanol productivity of the strain is 30.77% on dried sweet potato-residuces used for fermented raw material. Its productivity of ethanol is 3.56% and 4.16% higher than that of the strain K ( control 1 ) and Xin Shi-I ( control 2 ) respectively. When it ferments saccharified liquid prepared from nonglutinous rice, the strain produces 35.38% of ethanol, about 7.64% higher than that of the strain M-85 ( control 3 ) . In ethanol fermentation of the dried sweet potato chips, its productivity of ethanol is 30.20%,about 5.23% higherh tat of the strain Xin Shi-I(control 2). It can be seen that the increase of ethanol production with the interspecific fusant HU-KDF-185 is quite remarkable and stable. It indicates that the interspecific fusant obtained by protoplast fusion is an excellent ethanol producer and has practical value in theethanol industry. We suggest that the protoplast fusion technique is useful for breeding new ethanol yeast strains, especially for some industrial yeasts which lack and/or have lost sexual phase in the life cycle.