Abstract

Antioxidant properties of exopolysaccharides (EPS) and intracellular polysaccharides (IPS) obtained respectively from mycelia and filtrates of submerged culture by Armillaria mellea in a 20-L stirred tank bioreactor wereinvestigated. Effective production of EPS and IPS is available by submerged culture of A. mellea with respective number average molecular weights and protein/polysaccharide ratios as 7.68×10⁶ Da and 7.68% as well as 5.65×10⁶ Da and 5.26%. Both EPS and IPS exhibit powerful antioxidant activities by conjugated diene method, chelating effect on ferrous ions and scavenging effect on superoxide anion, as evidenced by their quite low EC₅₀ values (< 5 mg/mL). Results confirmedthat fermented A. mellea polysaccharides are potential antioxidant sources of both healthy medicine and food industries.

Key words: Armillaria mellea, intracellular polysaccharide, exopolysaccharide, antioxidant activity.

Abbreviation

EPS, Exopolysaccharides; IPS, intracellular polysaccharides; BHA,butylated hydroxyanisole; EDTA, Ethylenediaminetetra acetic acid; AOA, antioxidant activity; DPPH, 1, 1-diphenyl-2-picrylhydrazyl.