普鲁兰生物合成中底物的作用及其生理机制  

Physiological Mechanism Underlying the Effect of Substrates on Pullulan Biosynthesis

作　　者：朱灿灿 陈晨 王大慧[1] 卫功元[1] ZHU Cancan;CHEN Chen;WANG Dahui;WEI Gongyuan(School of Biology and Basic Medical Sciences,Soochow University,Suzhou 215123,China)

机构地区：[1]苏州大学基础医学与生物科学学院

出　　处：《食品科学》2019年第14期63-68,共6页Food Science

基　　金：国家自然科学基金面上项目(21776189);江苏省自然科学基金面上项目(BK20181440);2017年苏州大学“■政基金”项目

摘　　要：以1株出芽短梗霉(Aureobasidium pullulans)CCTCC M 2012259为出发菌株,考察不同底物(葡萄糖、蔗糖和木糖)对普鲁兰分批发酵的影响。结果发现,蔗糖有利于实现普鲁兰的高产(72.33 g/L),而葡萄糖有助于获得更高的普鲁兰分子质量(5.9×105 Da)。通过对不同底物条件下的发酵动力学参数进行计算以及对相关生理生化指标进行测定,发现蔗糖提高了普鲁兰生物合成途径中的关键酶活性,增加了胞内尿苷二磷酸葡萄糖水平和能量物质ATP的供给,促进了普鲁兰的高产;而葡萄糖降低了普鲁兰降解酶系的活性,最终将普鲁兰分子质量维持在更高的水平。研究结果部分揭示了底物影响普鲁兰生物合成的生理机制,同时也为实现不同分子质量普鲁兰的高效生产提供了可行的技术参考。The effect of different substrates such as glucose, sucrose and xylose on the production of pullulan by Aureobasidium pullulans CCTCC M 2012259 in batch fermentation was investigated. It was shown that sucrose was favorable to improve pullulan production to a maximum titer of 72.33 g/L, while glucose was propitious to achieve pullulan with a maximumfinal molecular mass of 5.9 × 10~5 Da. The fermentation kinetic parameters with different substrates were calculated and physiological and biochemical indexes were determined. Sucrose was indicated to increase the activities of key enzymes involved in the metabolic pathway for pullulan biosynthesis, improve the levels of intracellular uridine diphosphate glucose(UDPG), and increased the energy supply from ATP, ultimately resulting in an improvement of pullulan production. In addition, glucose decreased the activity of pullulan-degrading enzyme during batch fermentation,helping to maintain the molecular mass of pullulan at a higher level. The results presented in this study partially revealed the physiological mechanism underlying the effect of substrates on pullulan biosynthesis, which will provide a feasible approach for efficient production of pullulan with different molecular masses.

关 键 词：出芽短梗霉 普鲁兰 葡萄糖 蔗糖 木糖 分批发酵 

分 类 号：Q815[生物学—生物工程] TS201.3[轻工技术与工程—食品科学]