Idania L. López / CIC BiomaGUNE, San Sebastian, Spain
Alejandro H. Orrego / CIC BiomaGUNE, San Sebastian, Spain
Daniel Andrés-Sanz / CIC BiomaGUNE, San Sebastian, Spain
Fernando López-Gallego / CIC BiomaGUNE, San Sebastian, Spain
Topic: Biocatalysis and Sustainable Chemistry
In vitro biosynthetic pathways that condense and reduce molecules through coenzyme A (CoASH) activation demand energy and redox power in the form of ATP and NAD(P)H, respectively. Coenzymes must be orthogonally recycled by ancillary reactions that consume chemicals, electricity, or light, impacting the atom economy and/or the energy consumption of the system. Here, we exploited vinyl esters as dual acyl and electron donor substrates to synthesize β-hydroxy acids through a non-decarboxylating Claisen condensation, reduction and hydrolysis stepwise cascade, including a NADH recycling step, catalyzed by 4 enzymes. This self-sustaining cascade reached a 24 mM titer of 3-hydroxy butyrate (3-HB) without requiring ATP and simultaneously recycling 9.6 times CoASH and NADH. Additionally, with enzyme co-immobilization 8.3 mM of 3-HB was reached. With further immobilization optimization we can obtain a heterogeneous biocatalyst capable of transforming simple molecules into multi-functional ones.
