Morphological evolution of various fungal species in the presence and absence of aluminum oxide microparticles: Comparative and quantitative insights into microparticle‐enhanced cultivation (MPEC)

Abstract

The application of microparticle‐enhanced cultivation (MPEC) is an attractive method to control mycelial morphology, and thus enhance the production of metabolites and enzymes in the submerged cultivations of filamentous fungi. Unfortunately, most literature data deals with the spore‐agglomerating species like aspergilli. Therefore, the detailed quantitative study of the morphological evolution of four different fungal species (Aspergillus terreus, Penicillium rubens, Chaetomium globosum, and Mucor racemosus) based on the digital analysis of microscopic images was presented in this paper. In accordance with the current knowledge, these species exhibit different mechanisms of agglomerates formation. The standard submerged shake flask cultivations (as a reference) and MPEC involving 10 μm aluminum oxide microparticles (6 g·L−1) were performed. The morphological parameters, including mean projected area, elongation, roughness, and morphology number were determined for the mycelial objects within the first 24 hr of growth. It occurred that heretofore observed and widely discussed effect of microparticles on fungi, namely the decrease in pellet size, was not observed for the species whose pellet formation mechanism is different from spore agglomeration. In the MPEC, C. globosum developed core‐shell pellets, and M. racemosus, a nonagglomerative species, formed the relatively larger, compared to standard cultures, pellets with distinct cores.

Kinetic model to describe the morphological evolution of filamentous fungi during their early stages of growth in the standard submerged and microparticle‐enhanced cultivations

“…Kowalska et al, who for the first time performed the detailed quantitative analysis of the early stages of fungal growth in MPEC [23]. It comprised the temporal changes of size and shape parameters for the aforementioned species in the standard and MPEC shake flask processes.…”

“…The strains were maintained on agar slants prepared according to the recommendations of ATCC, as described in detail by Kowalska et al [23]. globosum ATCC 6205, and M. racemosus ATCC 7924.…”

“…These data originated from the previous experiments conducted in shake flasks [23] and from the bioreactor experiments performed in the current study. These data originated from the previous experiments conducted in shake flasks [23] and from the bioreactor experiments performed in the current study.…”

“…The individual shake flask run lasted for 24 h [23]. The individual shake flask run lasted for 24 h [23].…”

“…Media compositions were dependent on the species and were the same as the ones used previously [23]. , and Na 2 MoO 4 ⋅ 2H 2 O (50 mg L −1 ) was added.…”