【摘要】 采用紫外照射法对原始菌株进行诱变和筛选,得到一株高产普鲁兰变异菌株T1,使普鲁兰的转化率达30.14%,是原始菌株的5.7倍.通过正交设计实验对原始菌株与变异株T1的最佳发酵条件进行了比较,确定了变异株T1的最佳发酵条件为:蛋白胨0.5g/L,蔗糖50g/L,起始pH5.0.普鲁兰的转化率主要与氮源浓度有关.并对该变异株与原始菌株的发酵特征进行了研究,发现变异株的特征发生了根本性改变.更多还原

【Abstract】 The mutating and the screening of the original fungus were carried out by the ultraviolet radiation method to obtain a mutant species T1 of high producting pullulan and its transformation rate of pullulan could reach 30.14%, which is 5.7 times that of the original fungus. Meanwhile, by designed orthogonal experiments, the optimum fermentation conditions of the original fungus and the mutant fungus T1 were compared. The optimum fermentation conditions of the mutant fungus T1 are determined as follows i.e.,  peptone is0.5 g/L, saccharose 50 g/L, pH 5.0. The rate of the transformation of the carbohydrate is mainly related to the concentration of the nitrogen source in the mutated fungus fermentation. At the same time, the fermentation characteristics of the original fungus and the mutated fungus were also studied. It was found that the characteristics of the mutant fungus were greatly changed. 更多还原