Kinetic Modeling of Corn Fermentation with S. cerevisiae Using a Variable Temperature Strategy

Area of Science:

• Biochemical Engineering
• Fermentation Science
• Yeast Biotechnology

Background:

• Traditional fermentation processes typically operate at fixed temperatures.
• Optimizing fermentation temperature is crucial for maximizing ethanol yield and production efficiency.
• The yeast Saccharomyces cerevisiae is a key microorganism in industrial ethanol fermentation.

Purpose of the Study:

• To analyze the effect of controlled variable temperature on batch ethanol fermentation.
• To model and compare ethanol production under fixed versus dynamic temperature conditions.
• To evaluate the impact of temperature profiles on Saccharomyces cerevisiae fermentation kinetics.

Main Methods:

• Development of a nonlinear system model for batch ethanol fermentation.
• Utilizing corn as a substrate for Saccharomyces cerevisiae fermentation.
• Comparison of fermentation performance at five different fixed temperatures and one controlled variable temperature profile (decreasing from 40°C).

Main Results:

• Lower fixed temperatures resulted in higher ethanol yields but longer equilibrium times.
• Higher fixed temperatures accelerated yeast growth rates but increased cell decay.
• The controlled variable temperature model, decreasing from 40°C, showed a 20% increase in ethanol production over 60h compared to the highest fixed temperature batch.
• Within a 24h simulation, the controlled variable temperature model yielded higher ethanol concentrations than fixed temperature batches.

Conclusions:

• Controlled variable temperature fermentation offers potential advantages over fixed temperature methods for ethanol production.
• Dynamic temperature adjustments can enhance fermentation efficiency and ethanol yield, particularly in the short term.
• Further research into optimal variable temperature profiles could lead to significant improvements in industrial ethanol fermentation.