Impact of pellet size on growth and lignin peroxidase activity of Phanerochaete chrysosporium

We investigated the influence of pellet size on the growth and lignin peroxidase (LiP) productivity of Phanerochaete chrysosporium. Different pellet sizes were obtained by varying the vessel diameter under constant shaking conditions. Under these varying conditions the pellet size was in the range of 2-18 mm, while the number of pellets in a single vessel varied from around 1,200 in the Erlenmeyer flask to around 6 in the narrowest vessel. A correlation between the final pellet size and the shear rate was obtained, demonstrating that the pellet size is mainly affected by hydrodynamics. The growth of large pellets was described by a cubic growth model. Despite different pellet sizes, LiP activity appeared in all vessels, but the onset of LiP activity showed a delay based upon the pellet size, while maximal LiP activities varied by only 15%, being around 850 U/l.