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Techniques for the Evolution of Robust Pentose-fermenting Yeast for Bioconversion of Lignocellulose to Ethanol
Published on: October 24, 2016
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Production of clean pyrolytic sugars for fermentation
Marjorie R Rover1, Patrick A Johnston, Tao Jin
1Center for Sustainable Environmental Technologies, Iowa State University, Ames, IA 50011 (USA), Fax: (+1) 515-294-0997. mrrover@iastate.edu.
Chemsuschem
|April 8, 2014
Summary
Researchers developed a method to recover sugars from fast pyrolysis, removing inhibitory contaminants for fermentation. NaOH overliming proved most effective for detoxifying pyrolytic sugars, enabling robust growth in ethanol-producing Escherichia coli.
Area of Science:
- Biomass Conversion
- Chemical Engineering
- Biotechnology
Background:
- Fast pyrolysis generates pyrolytic sugars and phenolic compounds.
- These compounds are valuable but contain fermentation inhibitors.
- Efficient separation and detoxification are crucial for valorization.
Purpose of the Study:
- To develop a method for separating sugars and phenolic oligomers.
- To detoxify pyrolytic sugars for direct fermentation.
- To identify the optimal detoxification method for microbial growth.
Main Methods:
- Utilized a unique recovery system to separate "heavy ends" based on water solubility.
- Employed water washes to recover a sugar-rich aqueous phase.
- Investigated various detoxification methods, including NaOH overliming.
- Assessed microbial growth using ethanol-producing Escherichia coli.
Main Results:
- Achieved over 93% sugar recovery through two water washes.
- Identified low-molecular-weight acids, furans, and phenols as key contaminants.
- NaOH overliming demonstrated the highest efficacy in removing inhibitors.
- Maximized microbial growth measurements with NaOH-treated pyrolytic sugars.
Conclusions:
- Separate recovery of sugars and phenolics from fast pyrolysis is feasible.
- Water solubility differences enable efficient separation.
- NaOH overliming is an effective detoxification strategy for pyrolytic sugars.
- Detoxified pyrolytic sugars support robust fermentation with Escherichia coli.
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