[Effect of alternating milieu changes on specific substrate consumption in microorganisms].

Area of Science:

• Technical microbiology
• Bioprocess engineering
• Chemical reaction engineering

Background:

• Microorganisms in technical applications often experience fluctuating environmental conditions.
• These changes can lead to increased entropy production and substrate consumption.
• This increased consumption is counterproductive to achieving optimal substrate yield.

Purpose of the Study:

• To investigate the impact of alternating milieu changes on microbial growth and substrate consumption.
• To develop a simple model predicting microbial responses to environmental perturbations.
• To validate the model's predictions against experimental data.

Main Methods:

• A simple mathematical model representing biological conversion as an irreversible consecutive reaction was developed.
• The model's response to alternating perturbations was simulated using analogue and digital computers.
• Simulation results were compared with experimental data from microbial systems.

Main Results:

• The model accurately predicted the increase in specific substrate consumption under alternating milieu changes.
• Simulations showed good agreement with experimental observations.
• The model provides a simplified yet effective representation of microbial behavior.

Conclusions:

• The developed model is a valuable tool for understanding and predicting microbial responses in dynamic environments.
• This understanding is crucial for optimizing technical processes involving microbial growth, such as in recirculation reactors.
• The model's simplicity facilitates its application in the preparation and design of bioprocesses.