Bioconversion of L-Tyrosine into p-Coumaric Acid by Tyrosine Ammonia-Lyase Heterologue of Rhodobacter sphaeroides Produced in Pseudomonas putida KT2440.

Abstract

p-Coumaric acid (p-CA) is a valuable compound with applications in food additives, cosmetics, and pharmaceuticals. However, traditional production methods are often inefficient and unsustainable. This study focuses on enhancing p-CA production efficiency through the heterologous expression of tyrosine ammonia-lyase (TAL) from Rhodobacter sphaeroides in Pseudomonas putida KT2440. TAL catalyzes the conversion of L-tyrosine into p-CA and ammonia. We engineered P. putida KT2440 to express TAL in a fed-batch fermentation system. Our results demonstrate the following: (i) successful integration of the TAL gene into P. putida KT2440 and (ii) efficient bioconversion of L-tyrosine into p-CA (1381 mg/L) by implementing a pH shift from 7.0 to 8.5 during fed-batch fermentation. This approach highlights the viability of P. putida KT2440 as a host for TAL expression and the successful coupling of fermentation with the pH-shift-mediated bioconversion of L-tyrosine. Our findings underscore the potential of genetically modified P. putida for sustainable p-CA production and encourage further research to optimize bioconversion steps and fermentation conditions.