A Synthetic Biology approach for bacterial bioconversion of lignin into renewable chemicals
Acronym: LIGBIO

Project coordinator
- Timothy Bugg - University of Warwick - United Kingdom

Project leaders
- Eduardo Diaz - Centro de Investigaciones Biologicas-Agencia Estatal Consejo Superior Investigaciones Cientificas - Spain
- Stéphanie Baumberger - Institut National de la Recherch Agronomique - France
- Paul Law - Biome Bioplastics Ltd. - United Kingdom

Lignin is a polymer found as 15-30% of plant biomass, and is produced industrially as a low-value by-product of pulp/paper manufacture and biofuel production. It contains phenolic monomer units, hence it represents a possible renewable source of aromatic chemicals that are needed industrially to make plastics, pharmaceuticals and agrochemicals, currently derived from crude oil. As part of the effort to develop a sustainable European bio-based chemical industry, we wish to convert lignin into renewable chemicals, however, due to its highly inert structure, no commercial process has yet been developed for conversion of lignin to renewable chemicals. Recently Prof. Bugg’s group at Warwick have discovered two novel bacterial lignin-degrading enzymes, and have shown that the lignin breakdown pathways in Rhodococcus jostii RHA1 can be modified genetically in order to generate vanillin, a chemical used in the food/flavour industry. However, at present the metabolic pathways and regulatory systems for lignin breakdown in bacteria are not well understood.

Therefore, in this project we will study Pseudomonas putida KT2440, a lignin-degrading bacterium whose genome has been sequenced and whose aromatic metabolic network is the best known in bacteria, to elucidate the metabolic and regulatory networks for lignin degradation. We will then use this knowledge to reprogramme this bacterium, using high activity lignin-degrading enzymes, to produce two target chemicals that are of interest for the production of renewable bioplastics. With industrial partner Biome Bioplastics, we will then develop a fermentation-based process for the production of renewable aromatic chemicals from lignin.