Kinetic compartmentalization by unnatural reaction for itaconate production

Abstract

Physical compartmentalization of metabolisms using membranous organelles in eukaryotes is helpful for chemical biosynthesis to ensure the availability of substrates from competitive metabolic reactions. Bacterial hosts lack such a membranous system, which is one of the major limitations for efficient metabolic engineering. Here, we introduced kinetic compartmentalization as an alternative strategy to enable substrate availability from competitive reactions. This method utilizes a non-natural biochemical reaction performed by an engineered enzyme to kinetically isolate the metabolic pathways and ensure substrate availability for the desired reaction. As a proof of concept, we could successfully demonstrate kinetic separation for efficient itaconate production from acetate in Escherichia coli, mimicking the native mitochondrial membrane system in Aspergillus species. Despite the utilization of the non-preferred carbon source, kinetic compartmentalization could lead to substantial increases of itaconate in both yield and titer, suggesting enough potential of our strategy for broad applications in diverse engineering.