| In this study,the two-way fermentation of Eurycuma longifolia using Cordyceps militaris was carried out,and a new way to improve the efficacy of the higher-grade medicinal materials was explored.Based on the single factor method to determine the liquid fermentation conditions of C.militaris,the liquid fermentation conditions of C.militaris were further optimized by response surface analysis;the optimal conditions for bidirectional fermentation of C.militaris and E.longifolia were determined by orthogonal experiment,and the enzyme activity of cellulase in the fermentation broth was detected;the paper compared the antibacterial and antioxidative properties of fermentation products and E.longifolia extract.The main results are as follows:Using the concentration of extracellular polysaccharide and mycelial biomass as indicators,the three media were screened at a temperature of 25°C and a shaking speed of120 r·min-1,and finally we selected the medium No.2 as the best liquid medium.The fermentation temperature,the shaking speed and initial p H were used as the influencing factors,and the liquid fermentation conditions of C.militaris were determined by single factor method:the fermentation temperature was 25°C,initial p H was 6.0 and the shaking speed was 120 r·min-1.In order to optimize the liquid fermentation conditions of C.militaris,the optimal conditions for liquid fermentation of C.militaris were determined by response surface methodology.The optimal conditions are as follows:temperature was 25.09°C,the starting p H was 6.24 and the shaking speed was 124.5 r·min-1,in which time the silk biomass reached 9.58 g·L-1 and the extracellular polysaccharide concentration reached 2.52 g·L-1.The orthogonal experiment was used to optimize the conditions of two-way fermentation of E.longifolia and C.militaris.When the mycelial biomass was the target product,the optimal fermentation temperature was 26°C,the initial p H was 6.0,and the shaking speed was 120 r·min-1,E.longifolia added 1%;when the E.longifolia reduction rate is the target,the optimum fermentation temperature was 26°C,the initial p H was 6.0,the shaking speed was 120 r·min-1,and the amount of E.longifolia added is 2%.The cellulase activity of the supernatant of the fermentation broth was determined by DNS method,and the enzyme activity ofβ-glucosidase in the fermentation broth was determined to be 1.16 U·mg-1;with the two-way fermentation of C.militaris,the quality of E.longifolia was reduced from 1.50 g to 1.19 g,and the reduction rate was 20.56%.Microscopic observations before and after fermentation showed that the matrix structure of E.longifolia changed,and voids appeared.The results suggested that C.militaris can be transformed into E.longifolia matrix by liquid fermentation.The antibacterial activity of the two-way fermented E.longifolia fermentation broth of E.longifolia extract and C.militaris was tested with Staphylococcus aureus,Sarcandra serrata and Escherichia coli as indicator bacteria.The results showed that the bacteriostatic activity of C.militaris liquid fermentation was stronger than the two-way fermentation of C.militaris,and the two-way fermentation of C.militaris was stronger than that of E.longifolia extract.The oxidation resistance of the two-way fermentation broth was measured by using the mass concentration of the fermentation broth as a gradient.The results showed that the two-way fermentation of C.militaris fermentation broth had a certain reducing ability.The DPPH free radical scavenging rate and the hydroxyl radical scavenging rate of the fermentation broth were positively correlated with the mass concentration of the fermentation broth polysaccharide.Respectively,the IC50 of the fermentation broth polysaccharide concentration was 117.81 mg·L-1 and 358.56 mg·L-1.In this study,the two-way fermentation of E.longifolia liquids reduced the production cost and increased the production efficiency,which provided a theoretical basis for the large-scale production of functional fermented beverages in the future;at the same time,it expands the direction of fermenting medicinal materials with high degree of lignification by medicinal fungi,and provides a new way for structural modification of active ingredients of traditional Chinese medicinal materials,which is of great significance to improve the efficacy of Chinese herbal medicines and gradually realize the modernization of Chinese herbal medicines. |
