Optimization of the solvent-tolerant Pseudomonas putida S12 as host for the production of p-coumarate from glucose.

A Pseudomonas putida S12 strain was constructed that is able to convert glucose to p-coumarate via the central metabolite L: -tyrosine. Efficient production was hampered by product degradation, limited cellular L: -tyrosine availability, and formation of the by-product cinnamate via L: -phenylalanine. The production host was optimized by inactivation of fcs, the gene encoding the first enzyme in the p-coumarate degradation pathway in P. putida, followed by construction of a phenylalanine-auxotrophic mutant. These steps resulted in a P. putida S12 strain that showed dramatically enhanced production characteristics with controlled L: -phenylalanine feeding. During fed-batch cultivation, 10 mM (1.7 g l(-1)) of p-coumarate was produced from glucose with a yield of 3.8 Cmol% and a molar ratio of p-coumarate to cinnamate of 85:1.