Simultaneous saccharification and extractive fermentation of cellulosic substrates

Area of Science:

• Biotechnology
• Biochemical Engineering
• Renewable Energy

Background:

• Traditional alcohol fermentation occurs in aqueous environments, limited by reactant solubility and product inhibition.
• Ethanol extraction into a non-miscible phase can overcome inhibition, enhancing fermentation kinetics.

Purpose of the Study:

• To develop and evaluate a novel simultaneous saccharification and extractive fermentation (SSEF) process.
• To assess the impact of extractive fermentation on ethanol productivity and water consumption.

Main Methods:

• Development of a simultaneous saccharification and extractive fermentation (SSEF) process.
• Comparison with conventional non-extractive fed-batch simultaneous saccharification systems.
• Batch SSEF reactor experiments using Solka Floc as substrate and cellulase enzyme.

Main Results:

• Ethanol productivity increased by up to 65% compared to conventional systems, calculated on an aqueous phase volume basis.
• Significant reduction in water requirement for SSEF reactions compared to conventional simultaneous saccharification.
• Achieved 50% conversion of 25% Solka Floc in 48 hours within batch SSEF reactors with a 2.5% aqueous phase.

Conclusions:

• The novel SSEF process offers substantial kinetic benefits and improved efficiency for ethanol production.
• SSEF significantly reduces water consumption, presenting a more sustainable bioprocessing approach.
• This technology demonstrates high conversion rates and enhanced productivity, making it a promising alternative for industrial ethanol fermentation.