 Recent advances in enzyme technology have enabled the efficient breakdown of cellulose, the most abundant and recalcitrant component of lignocellulosic biomass. Two newly identified types of enzymes, CBM33 and GH61, are able to act on the surface of the insoluble substrate, introducing chain breaks into the polysaccharide chains without the need of first extracting them from their crystalline matrix. This enables the use of existing enzymes to increase the efficiency of the overall process, making it more cost-effective and environmentally friendly.