Enhancement of Triterpenoids formation of Antrodia cinnamomea in thin Stillage-submerged Culture by Shifting the Shaking Rate and Adding Soybean Oil

Abstract

Antrodia cinnamomea is an endemic medical mushroom in Taiwan. It is well known that the major effective components in this medical fungus are polysaccharides, triterpenoids, and steroids; it is found only in Taiwan. Its anti-tumour activity remains Current research interest is focused on its anti-tumour activity from secondary metabolites of triterpenoids. However, the main disadvantage of mycelia produced by liquid cultures is the quite small amount of triterpenoid. In this study, various cultivation strategies were tested to investigate their effects on the production of triterpenoids in thin stillage submerged cultures of A. cinnamomea. The results indicate that when thin stillage was reused in shaking flask culture at a constant speed, crude triterpenoids production reached the level of 43.04 mg/L at a low inoculum size of 1% at d-20, which was twice that of the control of high inoculum size of 10%. This study demonstrates that diminishing inoculum size has a significant effect on mycelia morphology, and could raise the generation of crude triterpenoids. The addition of soybean oil and corn starch could improve the production of crude triterpenoids to 78.53 mg/L, triple that of the control. Shifting the shaking rate was the most efficient method for improving triterpenoids production. When the shaking rate was shifted at d-8 and the rate maintained for 5 d, the level of crude triterpenoids rose to 152.62 mg/L, which was 7-fold that of the control. The results also demonstrate the feasibility of the reuse of thin stillage for liquid cultures of A. cinnamomea.