利用紫外线致死原生质体融合技术选育嗜杀啤酒酵母

本文利用紫外线致死原生质体融合技术,在对酿酒酵母(Sacchromyces cereuisiae)亲株CD4-W不做任何遗传标记的条件下,成功地将对紫外线敏感的嗜杀酵母(killer yeast)5174(α.radl ural[KIL-kd,crz~ro~r])菌株的嗜杀质粒转移到CD4—W中,并对5174菌株原生质体的形成及紫外线致死等条件进行了研究。 以PEG—6000作为融合促进剂,促使两种原生质体融合,获得的大量融合子经嗜杀活性检出实验、小型酿造实验、遗传稳定性实验、细胞形态及大小的测定、dsRNA质粒的提取及琼脂糖凝胶电泳等实验,最终选出5株遗传性能稳定的融合子:FP3—13,FP3—28,FP5—23,FP5—24,FP9—3。对实验结果的进一步分析表明:融合子遗传性状稳定,不仅含有供体菌5174的嗜杀质粒,而且还含有受体菌CD4—W良好的核基因,是遗传稳定的异质体。小型啤酒酿造实验表明:将融合子FP5—24用于啤酒酿造中,对于抵抗野生酵母的污染、净化发酵体系,保证啤酒纯种酿造的进行有明显效果。

The Studies on the Breeding of Killer Beer Yeast by the Useing of Killing Protoplast Fusion Technique

On condition that we don't make any genetic marks for recpient strain CD4-W,killer plasmid was introduced into it by the useing of UV. killing protoplast fusion technique. For the donor strain 5174 (a radl ural[KIL-kd,CrErOr] which was sensitived to the UV. ,studies on its conditions of protoplast formation and killed by UV. also had been carried out.In the presence of PEG-6000 ,two kinds of protoplast were impeled to fuse. After the experimants of killer character selecting, laboratory scale brewing experiments, generation more than fifteen times on selective medium,studies of cell morphology and size,the preparation of dsRNA killer plasmid and its agarose gel electrophoresis and so on,five fusants,i. e. FP3-13,FP3-28,FP5-23,FP5-24,FP9-3 were obtained. Analysing to the results showed that these fusants were stable heteroplasmons in genetics which contain both the killer plasmid of donor strain 5174 and the nuclear genotype of recepient strain CD4-W. They can inhibit the contamination of wild yeast and pruify fermentation system.