从感染白腐病的马铃薯中分离筛选了一株高产小核菌多糖菌株,命名为齐整小核菌SCL2010(Sclerotium rolfsii SCL2010),对菌株SCL2010发酵培养基的碳源、有机氮源进行优化,并对发酵过程中pH值的变化进行了研究.结果表明,以葡萄糖为碳源、玉米浆为有机氮源对菌株SCL2010进行发酵,小核菌多糖的产量、碳源转化率和产物合成速率分别达到28 g·L-1、56%和0.39 g·L-1·h-1,显著高于已有研究报道.在发酵产小核菌多糖的过程中,其pH值的变化与已有研究报道显著不同:其pH值从发酵开始迅速下降至3.0以下后开始缓慢上升至3.5~4.0;如果控制pH值则使小核菌多糖的产量显著降低,而草酸含量升高,以此推测小核菌多糖的合成可能与pH值的变化有关,后续将进行深入研究.%We isolated a scleroglucan high-yielding strain named Sclerotium rolfsii SCL2010 from potatoes suffered white rot,optimized carbon source and organic nitrogen source of fermentation medium,and investiga-ted pH value change in the fermentation process.The results showed that,in the fermentation with glucose as a carbon source and corn steep liquor as a nitrogen source,scleroglucan yield,nitrogen source conversion rate,and product synthetic rate were 28 g · L-1 ,56%,and 0.39 g · L-1 · h-1 ,respectively,which were significantly higher than those of previous studies.Different from the previous studies,the pH value dropped to below 3.0 at the initial stage while rose slowly to 3.5~4.0.When the pH value was controlled at a certain value,the sclero-glucan production decreased significantly but the oxalic acid content increased,which revealed the scleroglucan synthesis might be associated with the pH value change,and further study is required.
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