蛹拟青霉-金针菇菇柄双向固体发酵条件及抗氧化活性

Condition of bidirectional solid-state fermentation of Paecilomyces militaris and Flammulina velutipes of waste stalk and antioxidant activity

以金针菇废菇柄为研究材料,利用蛹虫草无性型蛹拟青霉为发酵菌种,对金针菇废菇柄进行了双向固体发酵。通过单因素试验研究了料液比(w/v)、料层厚度、接种量、发酵温度、发酵时间等因素对发酵菌质还原力的影响,并在此基础上,采用Box-Benhnken(BBD)试验设计,以发酵菌质还原力为响应值,对还原力影响较大的料液比、接种量、发酵温度3个因素为考查变量指标,进行3因素3水平多因素的响应面试验,优化了发酵条件,并测定了发酵菌质的主要成分和抗氧化能力。结果表明,蛹拟青霉发酵金针菇废菇柄的最优条件为:料液比1:1.5,料层厚度2cm,接种量15%,发酵温度24℃,发酵时间15 d。在此条件下发酵金针菇废菇柄的抗氧化能力到达83.46%,比未发酵前增加了16.16%。发酵金针菇菌质多糖是未发酵金针菇菇柄的1.8倍,虫草素含量达到90.9μg/g。金针菇菇柄发酵菌质对ABTS+、超氧阴离子自由基、羟自由基和DPPH自由基清除率分别比未发酵金针菇菌柄的清除率提高16.16%、17.13%、26.15%和18.34%。研究结果为进一步开发高值化金针菇废菇柄产品提供了理论依据。

This study was based on the theory of medicinal fungi "bi-directional new type solidfermentation engineering", with Flammulina velutipes wast stalk as research materials, using agamotype Paecilomyces militaris strains of Cordyceps militaris for fermentation, the F. velutipes wast stalk was bi-directional solid fermented. The effects of solid-liquid ratio(w/v), material thickness, inoculum size,fermentation temperature, fermentation time on the fermented product reducing force was studied by single factor experiment, and on this basis, three factors three levels of multiple factors response surface test proceeded using Box-Benhnken(BBD) test design, and using the reducibility of fermented product as the response value, and using the greater influence of solid-liquid ratio, inoculum size, fermentation temperature this three indicators having major effects on reducing force of examine variables as response value, the optimal fermentation conditions were determined. The results showed that the optimal conditions for the fermentation of F. velutipes wast stalk by P. militaris were as follows: solid-liquid ratio1:1.5, material thickness 2 cm, inoculum size 15%, fermentation temperature 24 ℃, fermentation time 15 d.Under these conditions, the antioxidant capacity of waste stalk of F. velutipes fermented reached 83.46%,which was 16.16% higher than that unfermented. The polysaccharide of fermented F. velutipes was 1.8 times of that of unfermented F. velutipes. The content of cordycepin in fermented F. velutipes reached 90.9μg/g. The scavenging rates of ABTS+, superoxide anion free radical, hydroxyl free radical and DPPH free radical were 16.16%, 17.13%, 26.15% and 18.34%, respectively. This study provides a theoretical basis for the further development of high-value F. velutipes waste stalk products.