RRC ID 35332
Author Dellomonaco C, Rivera C, Campbell P, Gonzalez R.
Title Engineered respiro-fermentative metabolism for the production of biofuels and biochemicals from fatty acid-rich feedstocks.
Journal Appl. Environ. Microbiol.
Abstract Although lignocellulosic sugars have been proposed as the primary feedstock for the biological production of renewable fuels and chemicals, the availability of fatty acid (FA)-rich feedstocks and recent progress in the development of oil-accumulating organisms make FAs an attractive alternative. In addition to their abundance, the metabolism of FAs is very efficient and could support product yields significantly higher than those obtained from lignocellulosic sugars. However, FAs are metabolized only under respiratory conditions, a metabolic mode that does not support the synthesis of fermentation products. In the work reported here we engineered several native and heterologous fermentative pathways to function in Escherichia coli under aerobic conditions, thus creating a respiro-fermentative metabolic mode that enables the efficient synthesis of fuels and chemicals from FAs. Representative biofuels (ethanol and butanol) and biochemicals (acetate, acetone, isopropanol, succinate, and propionate) were chosen as target products to illustrate the feasibility of the proposed platform. The yields of ethanol, acetate, and acetone in the engineered strains exceeded those reported in the literature for their production from sugars, and in the cases of ethanol and acetate they also surpassed the maximum theoretical values that can be achieved from lignocellulosic sugars. Butanol was produced at yields and titers that were between 2- and 3-fold higher than those reported for its production from sugars in previously engineered microorganisms. Moreover, our work demonstrates production of propionate, a compound previously thought to be synthesized only by propionibacteria, in E. coli. Finally, the synthesis of isopropanol and succinate was also demonstrated. The work reported here represents the first effort toward engineering microorganisms for the conversion of FAs to the aforementioned products.
Volume 76(15)
Pages 5067-78
Published 2010-8
DOI 10.1128/AEM.00046-10
PII AEM.00046-10
PMID 20525863
PMC PMC2916504
MeSH 2-Propanol / metabolism Acetone / metabolism Aerobiosis Biofuels* Carboxylic Acids / metabolism Escherichia coli / genetics* Escherichia coli / metabolism* Fatty Acids / metabolism* Fermentation Genetic Engineering* Metabolic Networks and Pathways / genetics* Recombination, Genetic*
IF 3.633
Times Cited 32
Prokaryotes E. coli ?