Optimizing microbioreactor cultivation strategies for Trichoderma reesei: from batch to fed-batch operations.

Area of Science:

• Biotechnology
• Microbiology
• Enzyme Engineering

Background:

• Filamentous fungi, particularly Trichoderma reesei, are key producers of industrial enzymes like cellulases.
• Cultivating and characterizing T. reesei strains is challenging due to complex morphology, despite advanced gene editing tools.

Purpose of the Study:

• To develop a high-throughput microbioreactor cultivation protocol for cellulase-producing T. reesei strains.
• To explore microscale fed-batch cultivation for optimizing industrial enzyme production conditions.

Main Methods:

• Developed and validated a batch cultivation protocol using the BioLector microbioreactor with adapted medium and high shaking frequency.
• Established a microscale fed-batch strategy using lactose as a dual-purpose inducer and carbon source.
• Correlated scattered light intensity with cell dry weight to monitor fungal biomass formation.

Main Results:

• Successfully established a robust batch cultivation protocol for T. reesei, overcoming morphological challenges.
• Demonstrated a strong correlation between scattered light intensity and fungal biomass.
• Achieved a threefold increase in cellobiohydrolase and fivefold increase in β-glucosidase activity using microscale fed-batch cultivation compared to batch processes.

Conclusions:

• Microbioreactor workflows are effective for optimizing T. reesei cellulase production and strain screening.
• Microscale fed-batch strategies show significant potential for enhancing enzyme production in industrial biotechnology.
• The developed protocol provides a valuable tool for assessing bioprocess parameters and advancing enzyme production applications.