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Butanol tolerance in a selection of microorganisms
1National Renewable Energy Laboratory, National Bioenergy Center, Golden, CO 80401, USA. eric_knoshaug@nrel.gov
Applied Biochemistry and Biotechnology
|December 18, 2008
Summary
Investigating butanol tolerance in microorganisms revealed that while most struggle above 2%, certain Lactobacillus strains can grow up to 3% butanol, offering potential for improved biofuel production.
Area of Science:
- Microbiology
- Biotechnology
- Biofuel Production
Background:
- Butanol production is limited by microbial tolerance, with current Clostridium strains unable to exceed 2% 1-butanol.
- Active butanol removal technologies are advantageous due to low microbial tolerance.
Purpose of the Study:
- To screen diverse microorganisms for enhanced butanol tolerance.
- To identify alternative microbial hosts for butanol production.
Main Methods:
- Screened 24 different microbial strains for butanol tolerance.
- Assessed growth inhibition thresholds in the presence of 1-butanol.
Main Results:
- A general growth barrier was observed between 1% and 2% butanol for most tested microorganisms.
- Escherichia coli, Zymomonas mobilis, and non-Saccharomyces yeasts failed to grow above 2% butanol.
- Two Lactobacillus strains demonstrated tolerance and growth at up to 3% butanol, outperforming Saccharomyces cerevisiae.
Conclusions:
- Lactobacillus species show significant promise as alternative hosts for butanol fermentation due to their high tolerance.
- Further research into Lactobacillus strains could overcome current butanol production limitations.
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