A thermostable β-1,6-endoglucanase or pustulanase (E.C. 3.2.1.75) which catalyses the cleavage of β-1,6 bonds in pustulan and other beta-glucans containing 1,6 linked glucose units. The
enzyme is now a component in a standard assay for beta-glucan from Baker’s yeast as documented in US Pharmacopeia Food and Chemicals Index.