AMYGDALIN DEGRADATION BY MUCOR-CIRCINELLOIDES AND PENICILLIUM-AURANTIOGRISEUM - MECHANISMS OF HYDROLYSIS

Mucor circinelloides LU M40 and Penicillium aurantiogriseum P 35 produ ce extracellular beta-glycosidases that are active on the cyanogenic g lycoside amygdalin. From the culture broths of M. circinelloides, only one beta-glycosidase could be identified, while two different enzymes - both having amygdalase activity - were found in culture broths of P . aurantiogriseum. The study of the mechanism of hydrolysis of the bet a-bis-glycoside amygdalin with purified enzymes from the two organisms indicated a possible sequential (two-step) reaction. In all cases, th e first step of hydrolysis from amygdalin to prunasin was very rapid, while the second step from prunasin to cyanohydrin was much slower. No cyanohydrin lyase activity was found in the culture broths of either fungus.