The direct conversion of plant cell wall polysaccharides into soluble sugars is one of the most important reactions on earth, and is performed by cer-tain microorganisms such as Clostridium thermocellum(Ct). These organ-isms produce extracellular multi-subunit complexes (. cellulosomes) comprising a consortium of enzymes, which contain noncatalytic carbohy-drate-binding modules (CBM) that increase the activity of the catalytic module.