L-Serine Dehydratase Activity in The Filamentous Fungus Alternaria chlamydospora

Cell-free extract of Alternaria chlamydospora was the most potent producer of L-serine dehydratase among 6 different fungi cell-free extracts. L-serine dehydratase of Alternaria chlamydospora produced during the logarithmic phase of growth. Maximal growth and enzyme production were obtained at the third day of growth. Also static cultures was better than shaking cultures for the growth of Alternaria chlamydospora and L-serine dehydratase synthesis. Maximum enzyme formation and growth of Alternaria chlamydospora was obtained at pH 5. L-serine dehydratase was induced by L-serine and L-threonine, alanine and glutamic acid, but L-serine and L-threonine were the best inducers. The effect of different carbon sources on growth and enzyme formation were studied. Its clear that the starch was the best for the growth and sucrose was the best for enzyme synthesis. Of the tested metal salts, FeSO4 was the best inducers for growth, while L-serine dehydratase synthesis was not affected by any metal. The effect of different vitamins on growth and enzyme synthesis was studied