LAUSR

Abstract Species-dependent mechanisms of morphological development affect filamentous fungi cultivations. In order to influence fungal morphology microparticle-enhanced cultivations (MPEC) were used towards four species exhibiting various mechanisms of morphology formation: a spore agglomerative Aspergillus terreus, hyphae agglomerative Penicillium rubens, spore and hyphae agglomerative Chaetomium globosum and non-agglomerative Mucor racemosus. The experiments were performed in stirred tank bioreactors as one-stage (inoculation with spores) and two-stage (inoculation with 24 -h shake flask preculture) MPEC and standard processes. Fungal morphology was quantified with the use of image analysis. The addition of Al2O3 microparticles to the bioreactor cultures changed the size and shape of mycelial objects of spore agglomerating A. terreus and non-agglomerating M. racemosus the most. The simultaneous action of microparticles and mechanical forces was the strongest for C. globosum, the fungus that combines both hyphae and spore agglomeration mechanisms of morphological development. The weakest effect of microparticles was observed for P. rubens, whose mechanism is hyphae agglomerative. Ultimately, MPEC was more effective in two-stage processes.