Researchers from the Institut Francais du Petrole (IFP, France) report a comparative kinetic analysis of beta-glucosidase enzymes from two fungal sources: Aspergillus niger (Novozymes SP 188) and Trichoderma reesei (BGL1). Beta-glucosidase is one of three major types of cellulose-degrading enzymes (collectively called "cellulases") which act synergistically in the degradation of cellulosic biomass to glucose. (The glucose is eventually fermented to biofuel ethanol). Beta-glucosidases catalyze the final reaction in the cellulose degradation step, the release of glucose from a small cellulosic fragment called "cellobiose". The researchers fitted the enzyme reaction data with a kinetic model called "Michaelis-Menten" kinetics, incorporating competitive inhibition. The results showed that the SP 188 beta-glucosidase (Aspergillus niger) had a lower specific enzyme activity and was more sensitive to glucose inhibition, compared to BGL1 (Trichoderma reesei). The researchers mention that the results can help define "optimal enzymatic cocktails" for new beta-glucosidase activities. The study is published in the open-access journal, Biotechnology for Biofuels (URL above)..