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Continuous Liquid-Liquid Extraction of Medium-Chain Fatty Acids from Fermentation Broth Using Hollow-Fiber Membranes
Published on: August 9, 2024
Membrane-mediated extractive fermentation for lactic acid production from cellulosic biomass
Applied Biochemistry and Biotechnology
|April 1, 1997
Summary
This study optimized lactic acid production from cellulosic biomass using a novel fermenter-extractor. A tailored solvent mixture and a progressive pH shift significantly enhanced simultaneous saccharification and extractive fermentation efficiency.
Area of Science:
- Biotechnology
- Biochemical Engineering
- Industrial Microbiology
Background:
- Lactic acid is a valuable chemical produced from biomass.
- Efficient production requires overcoming product inhibition and optimizing fermentation conditions.
- Simultaneous saccharification and fermentation (SSF) offers advantages but faces challenges in product recovery.
Purpose of the Study:
- To develop and optimize a bioreactor system for enhanced lactic acid production from cellulosic biomass.
- To investigate the efficacy of in situ extraction using a microporous hollow fiber membrane (MHF) bioreactor.
- To evaluate the impact of a novel solvent mixture and a dynamic pH strategy on fermentation performance.
Main Methods:
- Utilized a fed-batch fermenter-extractor with a microporous hollow fiber membrane (MHF) for continuous lactic acid removal.
- Employed a tertiary amine (Alamine 336) enhanced with long-chain alcohols (oleyl alcohol) and a diluent (kerosene) as the extraction solvent.
- Implemented a progressive pH change from 5.0 to 4.3 during simultaneous saccharification and extractive fermentation.
Main Results:
- A solvent mixture of 20% Alamine 336, 40% oleyl alcohol, and 40% kerosene demonstrated optimal lactic acid extraction.
- The dynamic pH strategy significantly improved overall fermentation performance compared to constant pH operation.
- Continuous extraction via MHF effectively mitigated product inhibition, enhancing lactic acid yield.
Conclusions:
- The developed MHF bioreactor system with optimized solvent and dynamic pH control is highly effective for lactic acid production from cellulosic biomass.
- This integrated approach enhances efficiency by combining simultaneous saccharification, extractive fermentation, and continuous product removal.
- The findings present a promising strategy for sustainable and cost-effective industrial-scale lactic acid manufacturing.
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