Exopolysaccharides produced by Antrodia cinnamomea using microparticle-enhanced cultivation: Optimization, primary structure and antibacterial property.

Microparticle-enhanced cultivation was used to enhance the production of exopolysaccharides (EPSs) from Antrodia cinnamomea. The structure and antibacterial activity of two EPSs produced by A. cinnamomea treated with Al2O3 [EPS-Al (crude) and EPS-Al-p (purified)] and without Al2O3 [EPS-C (crude) and EPS-C-p (purified)] were compared. It was observed that the addition of 4 g/L Al2O3 at 0 h resulted in the highest EPS yield of 1.46 g/L, possible attributed to the enhanced permeability of the cell membrane. The structural analysis revealed that EPS-C-p and EPS-Al-p had different structures. EPS-C-p was hyperbranched and spherical with a Mw of 10.8 kDa, while EPS-Al-p was irregular and linear with a Mw of 12.5 kDa. The proportion of Man in EPS-Al-p decreased, while those of Gal and Glc increased when compared to EPS-C-p. The total molar ratios of 6-Glcp and 4-Glcp in EPS-Al-p are 1.45 times that of EPS-C-p. Moreover, EPSs could alter bacterial cell morphology, causing intracellular substance leakage and growth inhibition, with EPS-Al having a stronger antibacterial activity than EPS-C. In conclusion, A. cinnamomea treated with Al2O3 could produce more EPSs, changing monosaccharide composition and glycosidic linkage profile, which could exert stronger antibacterial activity than that produced by untreated A. cinnamomea.

Efficient production of Antrodin C by microparticle-enhanced cultivation of medicinal mushroom Antrodia cinnamomea.

The microparticle-enhanced cultivation (MPEC) was used to enhance the production of Antrodin C by submerged fermentation of medicinal mushroom Antrodia cinnamomea. The crucial factors such as types, sizes, concentrations, and addition time of microparticles were optimized. The mechanism of MPEC on the membrane permeability and fluidity of A. cinnamomea and the expression of key genes in Antrodin C were investigated. When talc (18 µm, 2 g/L) was added into the fermentation liquid at 0 h, the promoting effect on Antrodin C was the best. The maximum yield of Antrodin C was 1615.7 mg/L, which was about 2.98 times of the control (541.7 mg/L). Talc slightly damaged the mycelia of A. cinnamomea, increased the release of intracellular constituents, and enhanced the index of unsaturated fatty acid. In addition, the key genes (IDI, E2.3.3.10, HMGCR, atoB) that might play an important role in the synthesis of the triquine-type sesquiterpene Antrodin C, were upregulated. In conclusion, talc increased the permeability and fluidity of cell membrane, upregulated the key genes and improved the biosynthesis process to enhance the yield of Antrodin C in the submerged fermentation of A. cinnamomea.