[Physicochemical properties of medicinal fungus Polyporus umbellatus sclerotial exudate].

This study was conducted to investigate the physicochemical properties of Polyporus umbellatus sclerotial exudate. Morphological characteristics of the sclerotia and its exudate were observed during different stages of sclerotial formation. The pH of the exudate was detected at different time during cultivation. A phenol-sulfuric acid method was employed to determine the polysaccharide content of P. umbellatus sclerotial exudate during cultivating time. Additionally, the protein content was measured by means of BCA protein assay. Furthermore, CAT content was detected using ultraviolet absorption method. That the protein content of the exudate and CAT specific activity rose gradually during the passage of the cultivating time indicated a high level of oxidative stress during P. umbellatus sclerotial exudate formation. The results showed that the pH of the exudate increased gradually and then dropped down during sclerotial formation. That the pH of the exudate maintained the acidity state during the cultivation indirectly indicated that acidic environment would help sclerotial formation. The exudate produced gradually and was absorbed by the sclerotia itself.