LAUSR

The large surplus of glycerol derived from the expanding biofuel industry raises economic and environmental concerns regarding disposal. In vitro synthetic biology is emerging as a useful biomanufacturing platform while the conversion of glycerol is rarely investigated. Here we develop a thermostable in vitro synthetic biosystem consisting of three enzymatic cascades for the biotransformation of glycerol into valuable chemicals with different degrees of reduction. Condensation of glycerol, phenol, and ammonium into l-tyrosine is achieved using four enzymes without the assistance of NAD+/NADH-related redox reactions. Production of chemicals with high degrees of reduction (e.g., optically pure l-lactate and d-lactate) is also verified through coupling with an NADH-regeneration system. The biotransformation of glycerol and ammonium into l-serine is achieved using four enzymes with self-sufficient NADH recycling.Glycerol is an abundant byproduct of the biofuel industry which holds promise as a platform chemical. Here glycerol is converted to value-added chemicals of varying degrees of reduction using thermostable multi-enzyme cascades.