Medium modification to enhance the formation of bioactive metabolites in shake flask cultures of Antrodia cinnamomea by adding citrus peel extract

摘要

Antrodia cinnamomea has recently become a well-known medicinal mushroom in Taiwan. Bioactive compounds found in A. cinnamomea include: polysaccha-ride, sesquiterpene lactone, steroids and triterpenoids. The aim of this study was to evaluate the feasibility of adding citrus peel extract to enhance the formation of bioactive metabolites in the submerged culture of A. cinnamomea. With the exception of grapefruit, citrus peel extracts tested were proved to be beneficial to mycelial growth and to the production of intracellular polysaccharide. Lemon was the most effective for enhancing bioactive metabolite production. With an addition of 2% (v/v), the mycelium biomass concentration and intracellular polysaccharide content rose from 11.96 g DW/L of the control and 123.6 mg/g DW to 21.96 g DW/L and 230.8 mg/g DW, respectively, on day 8. The production of triterpenoids also increased from 86.7 to 282.9 mg/L. Moreover, this study also demonstrates that although the addition of peel extract could cause the lengthening of the exponential phase and reduce the specific growth rate, the production rate of biomass, intracellular polysaccharide and triterpenoids was still enhanced significantly.