Exopolysaccharide biosynthesis and related enzyme activities of the medicinal fungus, Ganoderma lucidum, grown on lactose in a bioreactor

Exopolysaccharide (EPS) production and biosynthesis were studied in Ganoderma lucidum, a fungus used in traditional Chinese medicine, grown with lactose in a bioreactor. -Galactosidase activity, which implies the existence of a lactose permease system, was induced by lactose. Lactose feeding also increased -phosphoglucomutase activity and EPS accumulation but decreased phosphoglucose isomerase activity and lactate concentration in the culture broth. A maximum cell density of 22 g l^–1 and EPS at 1.25 g l^–1 were obtained in fed-batch bioreactor culture.