A dual cellular–heterogeneous catalyst strategy for the production of olefins from glucose

Living systems provide a promising approach to chemical synthesis, having been optimized by evolution to convert renewable carbon sources, such as glucose, into an enormous range of small molecules. However, a large number of synthetic structures can still be difficult to obtain solely from cells, such as unsubstituted hydrocarbons. In this work, we demonstrate the use of a dual cellular–heterogeneous catalytic strategy to produce olefins from glucose using a selective hydrolase to generate an activated intermediate that is readily deoxygenated. Using a new family of iterative thiolase enzymes, we genetically engineered a microbial strain that produces 4.3 ± 0.4 g l−1 of fatty acid from glucose with 86% captured as 3-hydroxyoctanoic and 3-hydroxydecanoic acids. This 3-hydroxy substituent serves as a leaving group that enables heterogeneous tandem decarboxylation–dehydration routes to olefinic products on Lewis acidic catalysts without the additional redox input required for enzymatic or chemical deoxygenation of simple fatty acids. A dual cellular-then-heterogeneous catalysis strategy has been used to produce olefins from glucose. 3-Hydroxy acids are made using an engineered microbial host. A hydrolytic step then provides the driving force for fatty acid deoxygenation by simple heterogeneous Lewis acid catalysis. This decarboxylation–dehydration route to olefinic products avoids the need for an additional redox input typically required for deoxygenation of unmodified fatty acids.