Hydrolyzes p-nitrophenyl beta-D-glucoside, p-nitrophenyl beta-D-mannoside, cellobiose, 4-methylumbelliferyl-beta-D-glucoside, laminarin, amygdalin, esculin and gentiobiose. Hydrolysis of terminal, non-reducing beta-D-glucosyl residues with release of beta-D-glucose. Homodimer. Formation of the homodimer is zinc-dependent (Potential). Belongs to the glycosyl hydrolase 1 family.