Advanced digital image analysis method dedicated to the characterization of the morphology of filamentous fungus.

Abstract

Filamentous fungi have a complex morphology that induces fermentation process development issues, as a consequence of viscosity increase and diffusion limitations. In order to better understand the relationship between viscosity changes and fungus morphology during fermentations of Trichoderma reesei, an accurate image analysis method has been developed to provide quantitative and representative data for morphological analysis. This method consisted of a new algorithm called FACE that allowed sharp images to be created at all positions, segmentation of fungus, and morphological analysis using skeleton and topological approaches. It was applied and validated by characterizing samples of an industrial strain of Trichoderma reesei that had or had not been exposed to an extreme shear stress. This method allowed many morphological characteristics to be identified, among which nine relevant criteria were extracted, regarding the impact of shear stress on the fungus and on the viscosity of the fermentation medium.