Processing characteristics of submerged fermentation of Antrodia cinnamomea in airlift bioreactor

Three 5-L airlift bioreactors including airlift reactor with solid draft tube (ALs), airlift reactor with net draft tube (ALn) and bubble column reactor (BC) were investigated for their suitability for cultivating Antrodia cinnamomea, and a stirred tank reactor (ST) was used for comparison. Results indicated that after 7 days fermentation, ALs yielded the highest mycelium content (313 mg/100 mL) and had the lowest dissolved oxygen in the broth. Among different aeration rates (0.025, 0.05, 0.1, 0.5, 1 vvm) used during cultivation of A. cinnamomea in ALs, the aeration rate 0.1 vvm resulted in a volumetric oxygen transfer coefficient of 10.8 h−1 and produced the highest mycelium content. When the optimal conditions were used for the fermentation of A. cinnamomea in an industrial 500-L ALs, the mycelium content in the broth reached 542 mg/100 mL in 28 days. The IC50 values of the ethanol extracts of A. cinnamomea mycelium cultivated in 5-L and 500-L ALs for 28 days were 23 and 17 μg/mL, respectively, for hepatocellular carcinoma cells HepG2. And after 42 days cultivation in 500-L ALs, the IC50 value of the mycelium ethanol extract was reduced to 10 μg/mL.

► Using airlift reactor with solid draft tube yielded the highest biomass content.
► Aeration rate of 0.1 vvm offered a better environment and increased biomass production.
► A. cinnamomea is sensitive to shear stress and prefers lower kLa.
► Scale up to 500-L airlift bioreactor will increase biomass production and time-saving.
► The ethanol extract of mycelium effectively inhibited proliferation of HepG2 cells.