Abstract:o explore the optimal selenium-tolerant strains in Pleurotus ostreatus and determine the culture conditions and mycelial characteristics, four kinds of Pleurotus ostreatus were screened by solid culture and liquid fermentation. Pleurotus djamor was selected to culture selenium-enriched mycelium. The enzymatic activity indicators and the in vitro antioxidant activities of mycelial proteins and polysaccharides were determined. The results determined Pleurotus djamor as the best selenium-tolerant species. The optimal culture conditions were as follows: shaking speed of 150 r/min, pH 6.5, temperature of 25 ℃, and selenium concentration of 5.0 mg/L. Compared with the conventional mycelium, the selenium-enriched mycelium promoted the activities of PPO, POD and SOD, improved the stress resistance of mycelium. The selenium-enriched mycelium and its polysaccharides and proteins had strong scavenging ability to DPPH, superoxide anion radical and hydroxyl radicals. Finally, the effect of selenium-enriched mycelium of Pleurotus djamor on the survival rate of Caco-2 cells was investigated, and it was found that the selenium-enriched mycelium could inhibit the survival rate of Caco-2 cells. The selenium-enriched liquid fermented mycelium of Pleurotus djamor has been preliminarily determined with high physiological activity, which could be considered as a selenium supplement.
