Polysaccharides production by submerged fermentation of Coprinus comatus and their inhibitory effects on non-enzymatic glycosylation

Abstract

Bioactive polysaccharides produced by fungi, especially by medicinal mushrooms, have attracted great interest. Polysaccharides from Coprinus comatus have been reported to possess hypoglycemic activity. In the present study, the effects of carbon source, initial glucose concentration and initial peptone level on cell growth and polysaccharide production were examined in the submerged fermentation system of C. comatus. Maltose was found to be disadvantageous for cell growth, but favorable for extracellular polysaccharide (EPS) production. Glucose was beneficial for both cell growth and production of intracellular polysaccharide (IPS), which was markedly improved when a high initial glucose concentration was used. The highest maximal EPS production level (0.89 g/l) was obtained with an initial glucose concentration of 40 g/l. Cell growth was positively related to increases in initial peptone concentration and polysaccharide production was maximized at 10 g/l of peptone. Finally, high inhibitory activity of Coprinus polysaccharides (both EPS and IPS) on non-enzymatic glycosylation (NEG) was demonstrated for the first time. The findings in this study can be applied to improve the performance of C. comatus cultures in the production of bioactive metabolites on a bioreactor scale and provide a foundation for further investigation into medicinally active compounds derived from C. comatus.