We selected Aspergillus niger GRM3 because it secreted a novel enzyme that hydrolyzed glycyrrhizinic acid. The enzyme was purified to the electrophorctically homogeneous state and an activity more than 890-fold that of culture broth. The molecular weight of the enzyme was estimated to be 150, 000 by gel filtration and it was most active over the range of pH 4.1 to 4.5. The enzyme hydrolyzed glycyrrhizinic acid to produce glycyrrhetinic acid and D-glucuronyl-β-1, 2-Dglucuronic acid. The hydrolytic action of this enzyme was different from those of β-glucuronidases reported so far.
Japan Society for Bioscience, Biotechnology, and Agrochemistry