Influence of nutritional components and oxygen supply on the mycelial growth and bioactive metabolites production in submerged culture of Antrodia cinnamomea

Abstract

Effects of carbon sources, nitrogen sources, plants oils and oxygen supply on the cell growth and production of bioactive metabolites such as exopolysaccharide (EPS), intracellular polysaccharide (IPS) and triterpenoid in the submerged culture of Antrodia cinnamomea CCRC36716 were studied in detail. Malt extract (ME), yeast extract (YE) and corn steep powder (CSP) were favorable nitrogen sources to the mycelial growth. The highest cell growth (12.52 ± 0.03 g/l cell dry weight), EPS production (1861 ± 62 mg/l) and IPS content (41 ± 12 mg/g DW) can be obtained on day 10 of cultivation in the medium containing 3% CSP, 3% YE, and 3% ME, respectively. The highest overall triterpenoid production (30 mg/g DW) was obtained in 3% CSP medium after 14 d of cultivation. Amongst five carbon sources examined, maltose and glucose yielded relatively high mycelial biomass; high cell densities of 8.29 ± 0.05 and 8.69 ± 0.05 g DW cells/l were obtained after 10 d of cultivation when 4% of maltose and glucose was used, respectively. Pronounced production of EPS, 1482 ± 63 and 1318 ± 48 mg/l, was obtained after 10 d of cultivation when 4% of lactose and sucrose was used, respectively. The maximum IPS content (49 ± 9 mg/g DW) was achieved in 4% glucose medium after 10 d of cultivation; the highest overall triterpenoid production (31 mg/g DW) was obtained in 2% glucose medium after 14 d of cultivation. All plant oils tested stimulated cell growth of A. cinnamomea, enhanced the production of IPS, but inhibited the triterpenoid production. EPS production was slightly inhibited with soy oil but enhanced by the other oils tested, and the maximal EPS production (1147 ± 47 mg/l) was obtained when 0.5% of peanut oil was supplemented. The high O 2 supply in the A. cinnamomea culture was favorable for cell growth and polysaccharide production, but was inhibitory on the triterpenoid production. The results obtained are useful in regulation and optimization of A. cinnamomea culture for efficient production of cell mass and bioactive metabolites such as EPS, IPS and tripterpenoids in the submerged culture.