The enzyme, characterized from the bacterium Parabacteroides distasonis, specifically hydrolyses (1->2)-beta-D-glucooligosaccharides to sophorose. The best substrates are the tetra- and pentasaccharides. The enzyme is not able to cleave the trisaccharide, and activity with longer linear (1->2)-beta-D-glucans is quite low. This enzyme acts in exo mode and is not able to hydrolyse cyclic (1->2)-beta-D-glucans.