Production of Substituted Styrene Bioproducts from Lignin and Lignocellulose Using Engineered Pseudomonas Putida KT2440.

Ferulic acid is a renewable chemical found in lignocellulose from grasses such as wheat straw and sugarcane. Pseudomonas putida is able to liberate and metabolise ferulic acid from plant biomass. Deletion of the hydroxycinnamoyl-CoA hydratase-lyase gene (ech) produced a strain of P. putida unable to utilise ferulic and p-coumaric acid, which was able to accumulate ferulic acid and p-coumaric acid from wheat straw or sugar cane bagasse. Further engineering of this strain saw the replacement of ech with the phenolic acid decarboxylase padC, which converts p-coumaric and ferulic acid into 4-vinylphenol and the flavour agent 4-vinylguaiacol, respectively. The engineered strain containing padC was able to generate 4-vinylguaiacol and 4-vinylphenol from media containing lignocellulose, or Green Value Protobind lignin as feedstock, and did not require the addition of an exogenous inducer molecule. Biopolymerisation of 4-vinylguaiacol and 4-vinylcatechol styrene products was also carried out, using Trametes versicolor laccase, to generate "biopolystyrene" materials on small scale. This article is protected by copyright. All rights reserved.