The influence of culture conditions on mycelial structure and cellulase production by Trichoderma reesei Rut C-30

The morphology of Trichoderma reesei Rut C-30, during submerged cultivation s in shake flask, was examined. The influence of the size inoculum and the composition of the fermentation medium on the morphology and cellulase prod uction was studied. Different inoculum sizes were studied but the significa tive change in fungus morphology was observed for spores concentration betw een 10(5) and 10(7) spores/ml (i.e. 10(2) and 10(4) spores/ml in pre-cultur e medium). In the medium without Tween 80, at low inoculum size, the majori ty of the pellets were large and well individualized, in contrast, at highe r inoculation densities small flocs were obtained, with higher production o f soluble protein and higher filter paper activity. It was found that the a verage pellet size seems to be inversely proportional to the inoculum size. Medium composition, namely Tween 80, also influences the morphology of T. reesei Rut C-30 and enzyme production. The presence of Tween 80 in fermenta tion medium inhibited the pellet formation of this strain. (C) 2000 Elsevie r Science Inc. All rights reserved.