Lignocellulose is the most abundant biopolymer on Earth, and thus represents a carbon feedstock that is not only regarded as a cheap, renewable and a sustainable energy source (biomethane, second generation bioethanol, and biohydrogen), but is also suitable for the paper industry and green chemistry (production of petroleum-free chemicals making use of platform molecules). Unfortunately, lignocellulosic biomass is highly recalcitrant to degradation because of its complex structure involving lignin. Various pre-treatments are available to convert lignocellulose into useful substrates but often these are not energy efficient and may release inhibitory compounds which can prevent further cellulose deconstruction. Interestingly, termites, which mainly thrive on dead material of vegetal origin, have developed complex and highly efficient strategies to degrade lignocellulose. Their unique consortia of microorganisms (found nowhere else in nature) with multiple capabilities and interacting with the hosts, is considered a micro-scale bioreactor, since it can dissimilate 74-99% of the ingested cellulose and around 65-97% of hemicellulose. Therefore the OPTILYS project has the major objectives to (1) investigate the complex and highly efficient higher termite lignocellulolytic system by a novel metatranscriptomic approach (high throughput RNA sequencing) also supported by a metagenomic study; (2) characterize the most interesting enzymes with lignocellulolytic activities, and (3) overproducing them in bacteria or yeast systems; (4) generating enzyme cocktails that would mimic the complex enzymatic system of the termites, and (5) testing them against crop residues, manure and any other renewable energy plant materials of interest, commonly applied to Anaerobic Digestion reactors. The knowledge gained throughout this project will mainly be orientated towards efficient and sustainable conversion of biomass into energy (biomethane and bioethanol), but would also be of interest for any other biorefinery that relies on the lignocellulose digestion, e.g. bioethanol, paper and pulp industry, and green chemistry.