Scientists from the RWTH Aachen University and the Max-Planck-Institut für Kohlenforschung (both in Germany) report the characterization of purified cellobiohydrolases and endoglucanases (both components of the enzyme, cellulases) using alpha-cellulose as substrate. They also showed in detail, how these cellulases adsorb and hydrolyze insoluble alpha-cellulose. Cellulases are multi-component enzymes which convert cellulose in plant biomass into sugars for bioethanol fermentation. Alpha-cellulose, on the other hand, is a highly refined form of cellulose (with some hemicelluloses), obtained from the strong alkali treatment of lignocellulosic biomass. It reportedly exhibits similar crystallinity and porosity with wood biomass and shows the natural structure of cellulose fibers. The researchers contend that alpha-cellulose is a better substrate to characterize cellulases (compared to the use of pure cellulose), because it better mimics alkaline pretreated biomass, which is a common process for lignocellulosic biomass pretreatment. Among the highlights of the study are: (1) adsorption models indicate that higher shaking frequencies increased the adsorption of cellulases into alpha-cellulose, resulting in increased enzyme activites, (2) purified cellulases displayed comparable activities only on insoluble alpha-cellulose. Details of the study are published in the open-access journal, Biotechnology for Biofuels (URL above).