Journal article
Engineering high-level production of fatty alcohols by Saccharomyces cerevisiae from lignocellulosic feedstocks
Fatty alcohols in the C12-C18 range are used in personal care products, lubricants, and potentially biofuels. These compounds can be produced from the fatty acid pathway by a fatty acid reductase (FAR), yet yields from the preferred industrial host Saccharomyces cerevisiae remain under 2% of the theoretical maximum from glucose.
Here we improved titer and yield of fatty alcohols using an approach involving quantitative analysis of protein levels and metabolic flux, engineering enzyme level and localization, pull-push-block engineering of carbon flux, and cofactor balancing. We compared four heterologous FARs, finding highest activity and endoplasmic reticulum localization from a Mus musculus FAR.
After screening an additional twenty-one single-gene edits, we identified increasing FAR expression; deleting competing reactions encoded by DGA1, HFD1, and ADH6; overexpressing a mutant acetyl-CoA carboxylase; limiting NADPH and carbon usage by the glutamate dehydrogenase encoded by GDH1; and overexpressing the.9-desaturase encoded by OLE1 as successful strategies to improve titer.
Our final strain produced 1.2 g/L fatty alcohols in shake flasks, and 6.0 g/L in fed-batch fermentation, corresponding to similar to 20% of the maximum theoretical yield from glucose, the highest titers and yields reported to date in S. cerevisiae. We further demonstrate high-level production from lignocellulosic feedstocks derived from ionic-liquid treated switchgrass and sorghum, reaching 0.7 g/L in shake flasks.
Altogether, our work represents progress towards efficient and renewable microbial production of fatty acidderived products.
Language: | English |
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Year: | 2017 |
Pages: | 115-125 |
ISSN: | 10967184 and 10967176 |
Types: | Journal article |
DOI: | 10.1016/j.ymben.2017.06.004 |
ADH6 protein, S cerevisiae Alcohol Dehydrogenase Aldehyde Oxidoreductases Animals DGA1 protein, S cerevisiae Diacylglycerol O-Acyltransferase Fatty Alcohols Gene Deletion Lignin Metabolic Engineering Mice Recombinant Proteins Saccharomyces cerevisiae Saccharomyces cerevisiae Proteins Stearoyl-CoA Desaturase delta-9 fatty acid desaturase fatty acid reductase lignocellulose