Catalysis

Biology

Yield (engineering)

Downstream processing

Metallurgy

Materials science

Fine chemical

Raw material

Lactone

Titer

Biochemistry

Commodity chemicals

Computational biology

Drug discovery

Chemical space

Immunology

Organic chemistry

Biosynthesis

Polyketide

Enzyme

Biorefinery

Chemistry

Metabolic engineering

Bioreactor

Yarrowia

Antibody

Synthetic biology

Fermentation

Yeast

Proceedings of the National Academy of Sciences

Polyketides represent an extremely diverse class of secondary metabolites often explored for their bioactive traits. These molecules are also attractive building blocks for chemical catalysis and polymerization. However, the use of polyketides in larger scale chemistry applications is stymied by limited titers and yields from both microbial and chemical production. Here, we demonstrate that an oleaginous organism (specifically, Yarrowia lipolytica) can overcome such production limitations owing to a natural propensity for high flux through acetyl-CoA. By exploring three distinct metabolic engineering strategies for acetyl-CoA precursor formation, we demonstrate that a previously uncharacterized pyruvate bypass pathway supports increased production of the polyketide triacetic acid lactone (TAL). Ultimately, we establish a strain capable of producing over 35% of the theoretical conversion yield to TAL in an unoptimized tube culture. This strain also obtained an averaged maximum titer of 35.9 ± 3.9 g/L with an achieved maximum specific productivity of 0.21 ± 0.03 g/L/h in bioreactor fermentation. Additionally, we illustrate that a β-oxidation-related overexpression (PEX10) can support high TAL production and is capable of achieving over 43% of the theoretical conversion yield under nitrogen starvation in a test tube. Next, through use of this bioproduct, we demonstrate the utility of polyketides like TAL to modify commodity materials such as poly(epichlorohydrin), resulting in an increased molecular weight and shift in glass transition temperature. Collectively, these findings establish an engineering strategy enabling unprecedented production from a type III polyketide synthase as well as establish a route through O-functionalization for converting polyketides into new materials.

Rewiring <i>Yarrowia lipolytica</i> toward triacetic acid lactone for materials generation

Rewiring Yarrowia lipolytica toward triacetic acid lactone for materials generation