Effects of extraction technology on bioactivities from polysaccharide-rich Ganoderma lucidum

Abstract

In this study, the polysaccharide-riched extract from Ganoderma lucidum was obtained by different extraction methods including hot water extraction (HWE), ultrasonic-assisted hot water extraction (UHWE), enzyme-assisted extraction (EAE), and ultrasonic-assisted enzyme extraction (UAEE). The total polysaccharide content in UAEE (3.721±0.134%) was higher than HWE (1.783±0.156%), UHWE (1.886±0.148%), and EAE (2.133±0.139%). The G. lucidum extract was then evaluated for antioxidant activity by 2,2-diphenyl-1-1picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods. The antibacterial activity was assessed via half-maximal inhibitory concentration (IC₅₀). The DPPH radical scavenging activity of extract from UAEE was 42.334%, while the result obtained from FRAP shows much better than HWE, UHWE, and EAE methods. Furthermore, G. lucidum extracted by UAEE showed antibacterial activity against Bacillus cereus, Bacillus subtilis, and Staphylococcus aureus with IC₅₀ in the range of 0.069-0.096 g/ml.