Improved Purity and Immunostimulatory Activity of β-(1→3)(1→6)-Glucan from Pleurotus sajor-caju Using Cell Wall-Degrading Enzymes

The objective of this work was to improve the purity of β-(1→3)(1→6)-glucan in the native triple helical structure from the fruiting bodies of Pleurotus sajor-caju for effective biological function using cell wall-degrading enzymes. A crude carbohydrate was extracted with hot water, then treated with crude xylanase and cellulase from Paenibacillus curdlanolyticus B-6. β-Glucan in the extract was purified to homogeneity with a single and symmetrical peak using 650M DEAE Toyopearl and Sepharose CL-6B column chromatography. The purity of β-glucan was confirmed by high-performance size-exclusion chromatography. Purified β-glucan was obtained at a purity of up to 90.2%. The Congo red reaction and atomic force microscopy indicated that the purified β-glucan exhibited a triple helix conformation. Purified β-glucan was able to effectively up-regulate the functions of macrophages such as nitric oxide (NO) and tumor necrosis factor (TNF-α) production.