Improvements In Ethanologenic Escherichia Coli and Klebsiella Oxytoca

Technical Report · Thu Sep 30 04:00:00 EDT 2010

DOI:https://doi.org/10.2172/992134· OSTI ID:992134

Nunn, David ^[1]

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1. Verenium Corporation

The current Verenium cellulosic ethanol process is based on the dilute-acid pretreatment of a biomass feedstock, followed by a two-stage fermentation of the pentose sugar-containing hydrolysate by a genetically modified ethanologenic Escherichia coli strain and a separate simultaneous saccharification-fermentation (SSF) of the cellulosic fraction by a genetically modified ethanologenic Klebsiella oxytoca strain and a fungal enzyme cocktail. In order to reduce unit operations and produce a fermentation beer with higher ethanol concentrations to reduce distillation costs, we have proposed to develop a simultaneous saccharification co-fermentation (SScF) process, where the fermentation of the pentose-containing hydrolysate and cellulosic fraction occurs within the same fermentation vessel. In order to accomplish this goal, improvements in the ethanologens must be made to address a number of issues that arise, including improved hydrolysate tolerance, co-fermentation of the pentose and hexose sugars and increased ethanol tolerance. Using a variety of approaches, including transcriptomics, strain adaptation, metagenomics and directed evolution, this work describes the efforts of a team of scientists from Verenium, University of Florida, Massachusetts Institute of Technology and Genomatica to improve the E. coli and K. oxytoca ethanologens to meet these requirements.

• Research Organization: Verenium Corporation
• Sponsoring Organization: USDOE
• DOE Contract Number: FC36-07GO17058
• OSTI ID: 992134
• Report Number(s): DOEGO17058
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
BIOMASS
DISTILLATION
ENZYMES
ESCHERICHIA COLI
ETHANOL
FERMENTATION
HEXOSES
KLEBSIELLA
PENTOSES
SACCHARIDES
SACCHARIFICATION
STRAINS
TOLERANCE