In their new study Veiter et al., ("Optimal process design space to ensure maximum viability and productivity in Penicillium chrysogenum pellets during fed-batch cultivations through morphological and physiological control") used a CytoSense to maximise viability and productivity in cultivation of fungi through morphological and physiological control.
Cultivation strategies of filamentous fungi are characterized by specific fungal morphologies encompassing several forms; ranging from homogeneously dispersed hyphae to dense agglomerates. Industrial bioprocesses using the fungi Penicillium chrysogenum favour the sphere-like pellet form, but this will often lead to biomass degradation, due to metabolic differences between the core and outer layers of the pellets. Therefore, at-line monitoring of pellets (as done with the CytoSense) is needed for robust process control, while subsequent analysis of derived morphological descriptors can help in maximizing viability and productivity in their fed-batch processing.
The goal of this study was to study the impact of the fermentation parameters (power input, dissolved oxygen concentration, substrate uptake) on morphology, biomass viability and productivity of fungi. Responses were analysed using novel morphological descriptors (pellet compactness and viable pellet layer) measured by a CytoSense.
Altogether, the following responses were determine by a CytoSense:
The authors envision the presented methodology (optimizing bioprocessing through morphological and physiological control) to be suitable for any organism where process performance is highly dependent on morphology, as for instance already adapted for glyco-engineered yeast (Pekarsky et al., 2018).
Besides the pelletí signal profiles, new features of CytoClus include scaling options (to prevent signal saturation) and interactive viewing of all imaged particles and their pulse shapes for faster definition of changes in cells.