北冬虫夏草固体发酵产胞外多糖条件的研究

Study on Exopolysaccharide Production with Solid-fermentation Conditions by Cordyceps militaris

[目的]研究北冬虫夏草固体发酵产胞外多糖的条件。[方法]采用固体发酵法培养北冬虫夏草,研究碳源和氮源种类、酵母粉含量、KH2PO4含量、初始pH值、接种量、种龄及发酵时间对北冬虫夏草发酵产胞外多糖的影响。[结果]单因素试验和正交试验表明,最佳的发酵条件为:大米∶米糠=90∶10,酵母粉1.0%、KH2PO40.25%、初始pH 6.0、种龄4 d、接种量8%(V/W)、温度28℃、固水比1∶1(W/V)、发酵时间6 d。在此发酵条件下,北冬虫夏草胞外多糖产量达38.625 mg/g.干基。[结论]该研究为开发新型动物保健饲料提供了理论支持。

[Objective] The aim was to study the solid-fermentation conditions of exopolysaccharide production by Cordyceps militaris.[Method] C.militaris was cultured by solid-fermentation method,and the effects of carbon sources,nitrogen sources,yeast powder content,KH2 PO4 content,initial pH value,amount of inoculum,seed age and fermentation time on the exopolysaccharide production of C.militaris were studied.[Result] The single factor tests and orthogonal test showed that,the best fermentation conditions were as follows∶ rice∶ rice bran =90∶ 10,yeast powder 1.0%,KH2PO4 0.25%,initial pH 6.0,seed age 4 days,amount of inoculum 8% （V/W）,temperature 28 ℃,solid-water ratio 1 ∶ 1 （W/V）,fermentation time 6 days.Under these conditions,the yield of exopolysaccharides reached 38.625 mg/g.dry substrate.[Conclusion] The study provided theoretical support for the development of new health feed of animal.