Promotion of ganoderic acid production in <i>Ganoderma</i> sinense by the addtion of an ether extract from <i>Eupolyphaga</i> sinensis, a medicinal insect

Abstract

To screen stimulators from Chinese medicinal insects for mycelial growth and ganoderic acid (GA) production by Ganoderma sinense, the fungus was inoculated into the media with and without supplementation of a medicinal insect extract. The results show that all the water and ether extracts from the medicinal insects had no significant stimulatory effect on the biomass production (P > 0.05), and the extracts of Hydrotrechus remigator and Mylabris phalerata significantly inhibited the mycelial growth. However, the ether extract of Eupolyphaga sinensis at a concentration of 60 mgL^-1 led to a significant increase in GA concentration from 187.6 ± 8.32 to 251.3 ± 11.27 mgL^-1 (P < 0.01). Analysis of fermentation kinetics of G. sinense suggests that glucose concentration in the E. sinensis extract treatment group decreased more quickly as compared to the control group in the last 4 days of fermentation process, while the GA biosynthesis was promoted at the same period. However, the culture pH profile was not affected by the addition of the ether extract of E. sinensis.

Key words: Medicinal fungus, Ganoderma sinense, submerged fermentation, Eupolyphaga sinensis, ganoderic acid.