Oxalate decarboxylase activity was present in liquid culture medium and mycelium of Agaricus bisporus. Enzyme activity in the
mycelium peaked at two-weekly intervals after primary growth phase and into secondary metabolism, with activity peaks in the
medium occurring 7 d later than in the mycelium. The enzyme was partially purified and had two isozymes with pIs 3.0 and 3.4.
Characterization of the protein by SDS–PAGE and Western blotting against a polyclonal antibody raised to oxalate decarboxylase
from Collybia velutipes showed a major protein band of 64 kDa. Oxalate decarboxylase was also detected in the fruit body up to the
cup stage of development. The pH optimum for the enzyme was 3.6 and temperature optimum was 35 °C.