Document Detail


Engineering Escherichia coli for biodiesel production utilizing a bacterial fatty acid methyltransferase.
MedLine Citation:
PMID:  21926202     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The production of low-cost biofuels in engineered microorganisms is of great interest due to the continual increase in the world's energy demands. Biodiesel is a renewable fuel that can potentially be produced in microbes cost-effectively. Fatty acid methyl esters (FAMEs) are a common component of biodiesel and can be synthesized from either triacylglycerol or free fatty acids (FFAs). Here we report the identification of a novel bacterial fatty acid methyltransferase (FAMT) that catalyzes the formation of FAMEs and 3-hydroxyl fatty acid methyl esters (3-OH-FAMEs) from the respective free acids and S-adenosylmethionine (AdoMet). FAMT exhibits a higher specificity toward 3-hydroxy free fatty acids (3-OH-FFAs) than FFAs, synthesizing 3-hydroxy fatty acid methyl esters (3-OH-FAMEs) in vivo. We have also identified bacterial members of the fatty acyl-acyl carrier protein (ACP) thioesterase (FAT) enzyme family with distinct acyl chain specificities. These bacterial FATs exhibit increased specificity toward 3-hydroxyacyl-ACP, generating 3-OH-FFAs, which can subsequently be utilized by FAMTs to produce 3-OH-FAMEs. PhaG (3-hydroxyacyl ACP:coenzyme A [CoA] transacylase) constitutes an alternative route to 3-OH-FFA synthesis; the coexpression of PhaG with FAMT led to the highest level of accumulation of 3-OH-FAMEs and FAMEs. The availability of AdoMet, the second substrate for FAMT, is an important factor regulating the amount of methyl esters produced by bacterial cells. Our results indicate that the deletion of the global methionine regulator metJ and the overexpression of methionine adenosyltransferase result in increased methyl ester synthesis.
Authors:
Parwez Nawabi; Stefan Bauer; Nikos Kyrpides; Athanasios Lykidis
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2011-09-16
Journal Detail:
Title:  Applied and environmental microbiology     Volume:  77     ISSN:  1098-5336     ISO Abbreviation:  Appl. Environ. Microbiol.     Publication Date:  2011 Nov 
Date Detail:
Created Date:  2011-11-03     Completed Date:  2012-02-21     Revised Date:  2012-05-01    
Medline Journal Info:
Nlm Unique ID:  7605801     Medline TA:  Appl Environ Microbiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  8052-61     Citation Subset:  IM    
Affiliation:
Energy Bioscience Institute, University of California, Berkeley, California 94720, USA. pnawabi@lbl.gov
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MeSH Terms
Descriptor/Qualifier:
Biofuels*
Escherichia coli / genetics*,  metabolism*
Fatty Acids / metabolism
Genetic Engineering*
Metabolic Networks and Pathways / genetics*
Methyl Ethers / metabolism
Methyltransferases / genetics,  metabolism*
Organisms, Genetically Modified*
Recombinant Proteins / genetics,  metabolism
S-Adenosylmethionine / metabolism
Substrate Specificity
Triglycerides / metabolism
Chemical
Reg. No./Substance:
0/Biofuels; 0/Fatty Acids; 0/Methyl Ethers; 0/Recombinant Proteins; 0/Triglycerides; 29908-03-0/S-Adenosylmethionine; EC 2.1.1.-/Methyltransferases; EC 2.1.1.15/fatty acid methyltransferase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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