Recombined E. coli is often used to synthesize large amounts of biological substances and substances similar to them.If you incorporate the gene of the enzyme necessary to make the desired substance, all you have to do is continue to nourish the bacteria and it will be synthesized in large quantities.However, with non-natural products, it is necessary to artificially select the necessary enzymes, and there is a problem that a large amount of by-products are produced.

　If you want to synthesize only what you want from many by-products in a synthesis that goes through many stages of chemical reactions, focus on the stage where branching to the by-products occurs and block unnecessary routes.This can be achieved by using enzymes with slightly different shapes, but at present there is a problem that branching cannot be completely blocked.Therefore, a method called metabolic filtering was conceived.First, prepare multiple enzyme variations for each reaction stage.It was discovered that even if the ability to block the branching of each enzyme is low, by changing these combinations, it is possible to block unnecessary branching in the entire reaction.This is a breakthrough method compared to blocking the pathway to by-products at only one stage of the reaction.

　By using this metabolic filtering, it is possible to selectively produce only the desired substance by the combination of enzymes, even if there is no enzyme with a high selection system.It is expected that this will enable the synthesis of medicines and other useful substances, which have been difficult until now.

Source:[Chiba University] Developed an innovative method for artificial biosynthesis of unnatural compounds (PDF)