Ligning valorization strategies based on the development of a specialized microbial community

There is an increasing interest in the development of biological routes for lignin depolymerization and valorization. Studies have been performed to elucidate the enzymatic routes and microorganism involved in lignin conversion. Considering that the vast majority of microorganisms are not likely to be cultivated in an isolated form, metagenomic approaches display great potential to gain further access to microorganisms, genes and metabolic pathways linked to lignin breakdown and upgrading into high value chemicals. The present work focused on the development of a lignin-degrading specialized community (CLig) and the application of a combination of metagenomics approaches, including comprehensive taxonomic characterization and binning-assembly for reconstruction of microbial genomes. All these efforts provide basis to portray the major bacterial pathways involved in lignin degradation and aromatic compounds conversion. From the analysis of massive DNA sequencing data, several microorganisms and enzymes linked to the metabolic pathways of interest were identified, thus constituting a promising resource of biological information for lignin valorization. Along with isolation and genome sequencing of lignolytic bacterial strain of potential biotechnological interest, pathways for lignin valorization was validated based on vanillin production from ferulic acid using feruloyl-CoA synthetase (fcs) and enoyl-CoA hydratase/aldolase (ech).