By investigating the shear effect on submerged cultivation of a traditional Chinese medicinal herb Ganoderma lucidum, a relatively high cell concentration of 13.8 g·L-1 by dry mass was obtained in bioreactor at an impeller tip speed (ITS) of 0.51m·s-1. At an ITS of 0.51,1.02 and 1.53m·s-1, a maximal production titer of intracellular polysaccharide was 2.64, 2.20 and 2.28g·L-1 and that of ganoderic acid was 306, 299 and 273g·L-1, respectively. Under these ITSs, the maximal mean projected area of dispersed hyphae was 3.70, 2.54 and 2.13×104μm2, and that of pellets was 0.91, 0.67 and 0.55mm2, respectively. The information obtained is useful for efficient submerged cultivation of mushrooms on a large scale.
