Polyphenol oxidase (PPO) activity varied in differentiation from hyphae to
rhizomorph and croute in A. mellea. In undifferentiated hyphae there was not
any PPO activity, while croute showed the highest activity. Electrophoresis in
the presence of SDS allows the detection of intensive enzyme forms of PPO,
and can also convert slower migrating enzyme forms to faster ones. Some
fluorescent compounds, as intense activators of PPO, show an intense band of
PPO in electrophoresis but not in the migrating band