Filamentous fungi as emerging cell factories for the production of aromatic compounds

Microbial production of aromatic compounds from renewable feedstocks has gained increasing interest as a means towards sustainable production of chemicals. The potential of filamentous fungi for production of aromatic compounds has nonetheless not yet been widely exploited. Notably, many filamentous fungi can naturally break down lignin and metabolize lignin-derived aromatic compounds. A few examples where a fungal cell factory, often of Aspergillus spp., is used to produce an aromatic compound, typically through the conversion of one compound to another, have already been reported. In this review, we summarize fungal biosynthesis of biotechnologically interesting aromatic compounds. The focus is on compounds produced from the shikimate pathway. Biorefinery-relevant efforts for valorizing residual biomass or lignin derived compounds are also discussed. The advancement in engineering tools combined with the increasing amounts of data supporting the discovery of new enzymes and development of new bioprocesses has led to an increased range of potential production hosts and products. This is expected to translate into a wider utilization of fungal cell factories for production of aromatic compounds.