Comment on "Revealing nature's cellulase diversity: the digestion mechanism of Caldicellulosiruptor bescii CelA".

Brunecky et al. (Reports, 20 December 2013, p. 1513) compared the cellulolytic activity of bacterial multimodular cellulase CelA with fungal Cel7A (cellobiohydrolase I from Trichoderma reesei). If more active Cel7A from another fungus were used as a reference enzyme under optimal conditions with β-glucosidase added, the reported difference between bacterial and fungal enzymes would be less dramatic.