Metabolic engineering of lipid catabolism increases microalgal lipid accumulation without compromising growth

TitleMetabolic engineering of lipid catabolism increases microalgal lipid accumulation without compromising growth
Publication TypeJournal Article
Year of Publication2013
AuthorsTrentacoste E.M, Shrestha RP, Smith S.R, Gle C., Hartmann A.C, Hildebrand M, Gerwick WH
JournalProceedings of the National Academy of Sciences of the United States of America
Date Published2013/12
Type of ArticleArticle
ISBN Number0027-8424
Accession NumberWOS:000327744900033
Keywordsalgal biofuel; biofuel production; chlamydomonas-reinhardtii; deprivation; diatom phaeodactylum-tricornutum; droplet; lysophosphatidic acid acyltransferase; metabolism; purification; RNAi; targeted manipulation; thalassiosira-pseudonana bacillariophyceae; transformation; Triacylglycerol

Biologically derived fuels are viable alternatives to traditional fossil fuels, and microalgae are a particularly promising source, but improvements are required throughout the production process to increase productivity and reduce cost. Metabolic engineering to increase yields of biofuel-relevant lipids in these organisms without compromising growth is an important aspect of advancing economic feasibility. We report that the targeted knockdown of a multifunctional lipase/phospholipase/acyltransferase increased lipid yields without affecting growth in the diatom Thalassiosira pseudonana. Antisense-expressing knockdown strains 1A6 and 1B1 exhibited wild-type-like growth and increased lipid content under both continuous light and alternating light/dark conditions. Strains 1A6 and 1B1, respectively, contained 2.4- and 3.3-fold higher lipid content than wild-type during exponential growth, and 4.1- and 3.2-fold higher lipid content than wild-type after 40 h of silicon starvation. Analyses of fatty acids, lipid classes, and membrane stability in the transgenic strains suggest a role for this enzyme in membrane lipid turnover and lipid homeostasis. These results demonstrate that targeted metabolic manipulations can be used to increase lipid accumulation in eukaryotic microalgae without compromising growth.

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