Cellulose degradation and cellulase formation by Phialophora malorum

Area of Science:

• Mycology
• Enzymology
• Biochemistry

Background:

• Fungal enzymes like cellulases are crucial for breaking down plant biomass.
• Understanding enzyme production and localization in fungi like Phialophora malorum is key to their ecological roles and biotechnological applications.

Purpose of the Study:

• To investigate the formation and location of cellulases and beta-glucosidase in Phialophora malorum.
• To determine the influence of different carbon sources on enzyme production.

Main Methods:

• Culturing Phialophora malorum on various carbon sources, including cellulose, carboxymethyl-cellulose, glucose, and cellobiose.
• Analyzing the presence and location (cell-free vs. cell-bound) of cellulase and beta-glucosidase activities.

Main Results:

• Cellulases were found to be both cell-free and cell-bound during growth on cellulose and carboxymethyl-cellulose.
• Glucose and cellobiose significantly repressed cellulase formation.
• Low carboxymethylcellulase activity was detected in glucose-grown mycelium.
• The unicellular stage of P. malorum did not grow on cellulose or carboxymethyl-cellulose, but mycelial growth occurred.

Conclusions:

• Carbon source availability significantly impacts cellulase and beta-glucosidase formation and localization in Phialophora malorum.
• Repression by glucose and cellobiose suggests specific regulatory mechanisms for enzyme synthesis.
• Mycelial development is favored over unicellular growth on complex carbon sources like cellulose.