Alcoholic fermentation with flocculant Saccharomyces cerevisiae in fed-batch process.

Area of Science:

• Biotechnology
• Biochemical Engineering
• Industrial Microbiology

Background:

• Ethanol production relies on efficient yeast fermentation to reduce industrial costs.
• Saccharomyces cerevisiae strains with flocculant characteristics are key for optimizing fermentation processes.

Purpose of the Study:

• To optimize alcoholic fermentation using a fed-batch process with Saccharomyces cerevisiae.
• To determine optimal conditions for maximizing ethanol yield and productivity.
• To develop a kinetic model for substrate and product inhibition.

Main Methods:

• Utilized Central Composite Design (CCD) to identify optimal fermentation parameters.
• Employed a fed-batch process with Saccharomyces cerevisiae.
• Developed a kinetic model to describe fermentation inhibition.

Main Results:

• Optimal conditions (170 g/L sucrose, 40% v/v inoculum, 6h filling time) yielded 92.20% theoretical yield and 6.01 g/L h productivity.
• Process modifications (medium recirculation, increased inoculum) reduced residual sucrose to 2.8 g/L in 9h, increasing yield to 92.75% and productivity to 9.26 g/L h.
• Developed kinetic model showed good fit with experimental data, with maximum specific growth rates of 0.103 h⁻¹ (model) and 0.080 h⁻¹ (reactor).

Conclusions:

• Fed-batch fermentation with Saccharomyces cerevisiae can be optimized for enhanced ethanol production.
• Process modifications are effective in improving fermentation efficiency and reducing residual substrate.
• The developed kinetic model accurately describes fermentation behavior and inhibition kinetics.