(164ah) Leveraging Propionate-Induced Growth Inhibition in Corynebacterium Glutamicum to Evolve Improved Methylmalonyl-CoA-Dependent Polyketide Synthases

Corynebacterium glutamicum is a promising yet largely unexplored host for the production of polyketide products. Here we evaluate the feasibility of using C. glutamicum as a host for engineered polyketide production. We introduced module-based strategies aimed at decreasing carbon loss and increasing the intracellular concentration of methylmalonyl-coenzyme A (a key precursor for polyketide production) to express heterologous polyketide biosynthetic pathways that use methylmalonyl-coA as a substrate. Based on the elucidation of the mechanism of propionate inhibition of growth, growth-coupled evolution strategy was introduced to rescue cell growth and evolve polyketide synthase in C. glutamicum. Results showed that introduction methylmalonyl-CoA dependent polyketide production pathway would relieve this propionate-induced growth inhibition, opening the door to leverage this fitness advantage for selection of evolved polyketide synthase. These experiments demonstrate that we can engineer this industrial host to express PKS enzymes heterologously and use them to condense methylmalonyl-coA into more complex products.