短梗霉最佳培养条件研究

STUDIES ON OPTIMAL CULTURE CONDITIONS OF AUREOBASIDIUM PULLULANS

本文针对短梗霉多糖高产菌N518号菌株在发酵时的营养、初始pH值、温度和氧气等发酵条件的需求进行了研究．利用五因素四水平的正交试验获得了蔗糖等五种营养成份的最佳组合及最适的培养条件．结果表明，在本研究的条件下该菌蔗糖的转化率可达到56.2％．

The requirements of nutritions, intital pH, oxygen and temperature by high-producibility Aureobasidium pullulans strain were studied in this work. In order to get the best concentration of sucrose, K2HPO4, (NH4)2SO4, yeast extract and peptone in the medium, a five factors and four levels orthogonal test was designed. Under optimal conditions the pullulan producibility was increased distinctly to a high conversion of 56.2% and a yield of 60.0 g/L from the intital 10% sucrose as compared to the conversion rate of 50.8% and yield of 24.5 g/L from the intial 5.0% sucrose in the primary test. The results show that the intital pH has a significant effect on the synthesis of pullulan, and so do oxygen and temperature; but incubation from 2.0% to 7.0% and fermentation time from 96 hours to 120 hours have no significant effect.