液态发酵法合成雪峰虫草活性成分的初步研究

摘要

目的:探索液态发酵法合成雪峰虫草活性物质的基础工艺,为雪峰虫草资源的综合开发提供必要技术支持.方法:利用液态发酵技术对雪峰虫草菌丝体进行培养,并通过培养基组成和培养条件控制来实现活性物质的高效合成.以雪峰虫草菌为出发菌株,分别考察不同碳源(蔗糖、葡萄糖和可溶性淀粉)、不同氮源(蛋白胨、酵母浸粉、酵母浸膏、硝酸钠、硝酸钾和尿素)、不同维生素B(维生素B1和复合维生素B)和不同初始pH(pH为4、5、6、7、8、9)对雪峰虫草菌丝生长和胞外多糖、胞内多糖、虫草酸、胞内三萜合成的影响,进而筛选最佳培养基成分.结果:最佳碳源为蔗糖,最佳氮源为酵母浸粉,最佳维生素B为维生素B1,最佳初始pH为8.在碳源为蔗糖、氮源为酵母浸粉、添加0.1 g/L维生素B1和初始pH为8时可得到较高的生物量和代谢产物积累水平.结论:雪峰虫草可在液态发酵体系高效积累代谢产物;可通过发酵过程优化控制,实现该菌株细胞生长和活性代谢产物合成的优化.%OBJECTIVE:To explore basic technology for synthesis of active ingredients of Ophiocordyceps xuefengensis,and provide necessary technical support for comprehensive development of O. xuefengensis sourse. METHODS:Submerged fermenta-tion method was used to cultivate the mycelium,achieving efficient synthesis of active ingredients by controlling medium composi-tion and cultivation conditions. Using the bacteria as starting strain,the effects of different carbon sources (sucrose,glucose and soluble starch),different nitrogen sources (peptone,yeast extract powder,yeast extract,sodium nitrate,potassium nitrate and urea),different vitamin B(vitamin B1 and vitamin B complex)and different initial pH(pH was set at 4,5,6,7,8 and 9,re-spectively)on mycelial growth,extracellular and intracellular polysaccharide synthesis,cordycepin synthesis and intracellular triter-penoid synthesis were investigated to screen the optimal medium composition. RESULTS:The optimal carbon source,nitrogen source,vitamin B and initial pH were sucrose,yeast extract powder,vitamin B1 and 8,respectively. High biomass and metabolite accumulation levels can be obtained when carbon source was sucrose,nitrogen source was yeast extract powder,adding 0.1 g/L vi-tamin B1 with initial pH of 8. CONCLUSIONS:O. xuefengensis can efficiently accumulate metabolites,and achieve the optimiza-tion of strain cell growth and synthesis of active metabolite by optimizing and controlling the fermentation process.