Characterization of Fungal Morphology using Digital Image Analysis Techniques

The use of filamentous fungi for the production of commercially important products is old but keeps increasing during the last decades. New classes of compounds are being added in the list of products of fungal fermentations as a result of progress in methodologies and applications of biotechnology. Fungi are morphologically complex organisms that differ in structure throughout their life cycle. In submerged fermentation fungal morphology may take distinct forms ranging from dispersed filaments to densely interwoven masses of mycelium known as pellets. Each morphological form has each own characteristics that have a critical impact on the overall process outcome. Dispersed growth results in highly viscous broths with pseudoplastic behavior that have a negative impact on mass and energy transfer rates resulting in higher energy input requirements. Due to the high industrial relevance of fungal morphology there has been a substantial development of tools and techniques to characterize morphology and extract quantitative information that can be used in process control and optimization studies. Digital image analysis is the state of the art method to characterize and quantify fungal morphology in the developmental process from spores to filamentous structures to pellets. The progress made in the area since the 1990s, when the first image analysis methods were reported, is discussed in detail throughout the review. Characterization of Fungal Morphology using Digital Image Analysis Techniques