Invited Oral Abstract Presentation

Engineering Yarrowia lipolytica for triacetic acid lactone production

Claire Palmer, Kelly Markham and Hal Alper, The University of Texas at Austin, Austin, TX, USA

2017 SIMB Annual Meeting and Exhibition

Yarrowia lipolytica, an industrially attractive, non-conventional yeast, boasts a high innate capacity to produce acyl-CoA derived molecules such as triacylglycerides. Here we demonstrate the potential of rewiring Y. lipolytica to divert this precursor pool away from lipids and into alternative molecules of interest. Specifically, we explored the production of the simple polyketide, triacetic acid lactone (TAL). TAL has been proposed as a biorenewable platform chemical that can be converted into many downstream products including sorbic acid. Previous efforts to produce TAL in hosts such as E. coli and S. cerevisiae have been limited by the availability of acyl-CoA precursors. We enabled TAL production in the precursor rich host, Y. lipolytica, through heterologous expression of 2-pyrone synthase, an enzyme from Gerbera hybrida that catalyzes the formation of TAL by condensation of acetyl-CoA and malonyl-CoA. We next performed a series of strain engineering approaches to boost TAL production by metabolically rewiring Y. lipolytica for enhanced precursor accumulation. Final strain characterization was conducted in bioreactors to further optimize production titer, rate, and yield. Ultimately, we established a strain that produced the highest titer of TAL reported to date in any host. Here we present the details of these genetic engineering efforts as well as the production characterization of the resulting strain.