Catalyzes the hydrolysis of phosphorylated beta-glucosides into glucose-6-phosphate (G-6-P) and aglycone. It has a high affinity for phosphorylated aromatic beta-glucosides (p-nitrophenyl-beta-glucoside, phenyl beta-glucoside, arbutin), with the exception of phosphorylated salicin, and a low affinity for phosphorylated beta-methyl-glucoside. Apparently, it has only a very limited role in the utilization of external beta-glucosides. 6-phospho-beta-D-glucosyl-(1->4)-D-glucose + H2O = D-glucose + D-glucose 6-phosphate Homotetramer. Constitutively expressed. Belongs to the glycosyl hydrolase 1 family.