Has highest activity on the linear beta-1,6-glucan pustulan. Lower activity against yeast glucan and laminarin (beta-1,3-glucans with beta-1,6-branches). No activity on colloidal chitin, pachyman, starch, cellulose, nigeran, dextran or gentobiose. Random hydrolysis of (1->6)-linkages in (1->6)-beta-D-glucans. Optimum pH is 5.0. At least 20% of maximum activity is retained between pH 4.0 and 7.0. Optimum temperature is 50 degrees Celsius. After 30 min incubation at 50 degrees Celsius in the absence of substrate 50% of activity is lost. By fungal cell walls. Belongs to the glycosyl hydrolase 30 family.