%0 Journal Article
%T Functional expression and characterization of five wax ester synthases in Saccharomyces cerevisiae and their utility for biodiesel production
%A Shuobo Shi
%A Juan Valle-Rodr¨ªguez
%A Sakda Khoomrung
%A Verena Siewers
%A Jens Nielsen
%J Biotechnology for Biofuels
%D 2012
%I BioMed Central
%R 10.1186/1754-6834-5-7
%X Here, heterologous WSs derived from five different organisms were successfully expressed and evaluated for their substrate preference in Saccharomyces cerevisiae. We investigated the potential of the different WSs for biodiesel (that is, fatty acid ethyl esters) production in S. cerevisiae. All investigated WSs, from Acinetobacter baylyi ADP1, Marinobacter hydrocarbonoclasticus DSM 8798, Rhodococcus opacus PD630, Mus musculus C57BL/6 and Psychrobacter arcticus 273-4, have different substrate specificities, but they can all lead to the formation of biodiesel. The best biodiesel producing strain was found to be the one expressing WS from M. hydrocarbonoclasticus DSM 8798 that resulted in a biodiesel titer of 6.3 mg/L. To further enhance biodiesel production, acetyl coenzyme A carboxylase was up-regulated, which resulted in a 30% increase in biodiesel production.Five WSs from different species were functionally expressed and their substrate preference characterized in S. cerevisiae, thus constructing cell factories for the production of specific kinds of wax ester. WS from M. hydrocarbonoclasticus showed the highest preference for ethanol compared to the other WSs, and could permit the engineered S. cerevisiae to produce biodiesel.Natural wax esters are typically esters of long-chain fatty acids and long-chain alcohols [1]; due to their special properties, they have been widely used in lubricants, cosmetics, linoleum, printing inks, candles and polishes. For example, wax esters consisting of fatty acids with 20 carbon atoms (C20) and C20 alcohols are outstanding lubricants [2]; wax esters consisting of C14 to C20 fatty acids and a C2 alcohol represent good diesel fuels [3]. Today, wax esters are harvested from plants and animal tissues, or generated by chemical synthesis using fossil sources, and this is considered to be the main limitation for their application due to the restricted availability and high costs of existing sources [2,4]. Thus, there is a strong demand
%K Biodiesel
%K fatty acid ethyl esters
%K metabolic engineering
%K Saccharomyces cerevisiae
%K wax ester synthase
%U http://www.biotechnologyforbiofuels.com/content/5/1/7