面包酵母子囊孢子的形成条件及细胞学研究

STUDIES ON THE CONDITION AND CYTOLOGY OF ASCOSPORE FORMATION OF BAKER’S YEAST

通过对面包酵母(Saccharomyces cerevisiae)耐干性菌株 X-8在几种生孢条件下生子囊孢子的研究,发现菌株 X-8生孢的最适培养基为 Kleyn 培养基,最适培养温度为28℃。在液体中生孢菌体需要大通气量,其生孢的最佳细胞群体密度为8.0×10^(?)个细胞/ml。同时还发现,即使在恒温条件下,菌株 X-8在秋天较其他季节更易生孢子。在上述条件下,比较 X-8和不耐干的 CY26菌株,结果菌株 X-8的生孢能力远远大于菌株 CY26。X-8的电镜照片显示出生孢过程中子囊内的一系列变化,即随着生孢时间的增加,造孢剩质逐渐减少,孢子及孢子壁逐渐完善与成熟。孢内的细胞核在孢子形成的整个过程中一直清晰可见。

A drought-resistant strain of baker's yeast(Saccharomyces cerevisiae),X-8 was studiedunder several sporulation conditions.Results showed that the optimum sporulation medium andcultivation temperature were Kleyn medium and 28℃ respectively.When cultivated in liquid,the strain sporulated best with the cell population density of 8.0×10~5 cells/ml and intense aera-tion.X-8 was observed to sporulate easier in fall than in other seasons.When compared witha drought-sensitive strain CY26 of baker's yeast under above conditions,X-8 showed muchgreater sporulation tendency.The electronic micrographs of X-8 indicated a series of chan-ges in the asci during sporulation,that is,as the sporulation went on,the epiplasm decreasedgradually,the spore and spore wall tended to perfect and mature.The nuclear zone in thespore was seen clearly throughout the whole sporulation process.These results elucidated thecytology of sporulation of baker's yeast in dynamic aspect.