Alcohols for fuel:Biological energy to

usable energyBeth Papanek

Three main alcohols:

Methanol Ethanol Butanol

History of Ethanol

biofuelsdigest.com

Potential Yield

History of Butanol

Produced commercially starting in the 1920’s

Source: Hans Blaschek

Ethanol vs. Butanol

Wikipedia: “Ethanol” “isobutanol”

Comparison

Source: Hans Blaschek

Quick Biochem overview…

Saccharomyces cerevisiae

Butanol Metabolism

Source: Hans Blaschek

Problem: Preferential Hexose consumption

Source: bio.miami.edu

38-50% Cellulose, 15-30% Lignin, 23-32% Hemicellulose in cellulosic plants

Possible Improvements: Genetic Engineering

Saccharomyces cerevisiae Gene expression

for xylose uptake Increased xylose

transport

Clostridium beijerinckii Inhibitor tolerance Metabolic

constraints Electron flow

References

Ezeji, T., Qureshi, N., Blaschek, H. (2007) Bioproduction of butanol from biomass: from genes to bioreactors. Current Opinion in Biotechnology. 18: 220-227.

Gray, K., Zhao, L., Emptage, M. (2006) Bioethanol. Current Opinion in Chemical Biology. 10: 141-146.

Nevoigt, E. (2008) Progress in Metabolic Engineering of Saccharomyces cerevisiae. Microbioloby and Molecular Biology Reviews. 72: 379-412.