Involved in the type II arabinogalactan (AG) side chains degradation (PubMed:30564851). Specifically releases the non-reducing terminal beta-1,6-galactobiose (beta-1,6-Gal2) from both dearabinosylated larch AG and polymeric beta-1,6-galactan chains by an exo-mode of action (PubMed:30564851). Shows lower activity with larch AG, and very weak activity with dearabinosylated gum arabic, gum arabic and potato galactan (PubMed:30564851). Can probably release beta-1,6-Gal2 from the internal side chains of type II AG (PubMed:30564851). Hydrolysis of (1->6)-beta-D-galactosidic linkages in arabinogalactan proteins and (1->3):(1->6)-beta-galactans to yield (1->6)-beta-galactobiose as the final product. kcat is 261 sec(-1) with beta-1,6-Gal3 as substrate. Optimum pH is 4.5 with beta-1,6-Gal3 as substrate. Optimum temperature is 40 degrees Celsius with beta-1,6-Gal3 as substrate. Belongs to the glycosyl hydrolase 30 family.