Effect of heat stress on production and in-vitro antioxidant activity of polysaccharides in Ganoderma lucidum

Ganoderma lucidum is a traditional Chinese medicine, and its polysaccharides possess diverse and significant pharmacological activities. This study aimed to investigate the polysaccharide production, molecular characteristics and in-vitro antioxidant activity of G. lucidum fruiting body after the mushroom was harvested and treated with heat stress (HS). HS enhanced the production of polysaccharides after harvest and treatment of 42 °C HS for 2 h, and that resulted in the highest polysaccharide yield of 10.50%, which was 45.63% higher than that of the control, while 37, 45 °C HS had no significant effect on the production. In terms of molecular characteristics, 42 °C HS significantly changed monosaccharide ratio of polysaccharides, but no apparent molecular weight and functional group changes were found in polysaccharides after HS treatment. The results of in-vitro antioxidant activity assay revealed that 42 °C HS significantly improved the antioxidant activities of polysaccharides at the concentration of 2 mg/mL. In conclusion, this study provides a promising strategy to improve the production of G. lucidum fruiting body polysaccharides.