(693d) Engineering Yarrowia Lipolytica for the Production of Triacetic Acid Lactone

Yarrowia lipolytica is an industrially attractive oleaginous yeast with a high innate capacity to produce acyl-CoA molecules, especially lipids. Recently, we sought to divert the flux of these precursors away from native products like fatty acids and toward the proposed biorenewable platform chemical triacetic acid lactone (TAL). To this end, TAL has been proposed as an industrially interesting molecule as it can be easily converted into existing downstream products including sorbic acid, which has a large global demand. Previous efforts to produce TAL in hosts such as E. coli and S. cerevisiae have been limited by the availability of acyl-CoA precursors. Here, we sought to use the 2-pyrone synthase enzyme isolated from Gerbera hybrida to establish TAL production in Y. lipolytica. This enzyme performs the iterative condensation of two malonyl-CoAs with an acetyl-CoA starter unit to ultimately form TAL. Initial, simple overexpression of this heterologous synthase was sufficient to produce modest titers. To further improve production, we performed a series of strain engineering approaches to increase flux toward acetyl-CoA and malonyl-CoA intermediates. Final strains were optimized in bioreactor fermentations to improve titer, rate, and yield. Ultimately, we engineered a strain of Y. lipolytica capable of titers far exceeding that of any previously published study. This talk will highlight these efforts of strain engineering leading to this unmatched microbial production of TAL.