Filamentous fungi constitute the degrader organisms par excellence due to their hydrolytic capability and wide distribution in nature. Among them, the so-called white-rot fungi preferentially degrade lignin from plant cell walls. This aromatic polymer is the natural barrier that must be removed for the utilization of cellulose and hemicelluose. The secretion of a very unspecific enzymatic system constituted mainly by oxidorreductases (laccases, peroxidases and oxidases that produce hydrogen peroxide) confers them the unique capability to degrade lignin and also a variety of recalcitrant aromatic pollutants.
On the other hand, there are other organisms in nature, ascomycete fungi principally, that are efficient degraders of cellulose and hemicelluloses from plant biomass generating monosaccharides fermentable by yeasts for 2nd generation bioethanol production. This biofuel is produced from sustainable feedstock which gives better balance on CO2 emission and do not compete with human food chain (non-food crops or inedible waste products). Nowadays, different commercial enzymatic complexes based on cellulases and xilanases mixtures are being assayed to hydrolyze polysaccharides from plant cell walls. However, yields might be notably raised by reducing the presence of inhibitors generated during the physic-chemical pretreatment of plant biomass.
The study of new fungal strains might provide new enzymes which efficiency to degrade aromatic pollutants, as well as to be used for lignocellulosic bioethanol production. Both aspects will be assayed in the frame work of the current project.