Production of Isoamylase from Rhizopus oryzae in Submerged Fermentation

This work mainly focus on factors relevant for improvement of enzyme hydrolysis by using Rhizopus oryzae MTCC 9642 in submerged fermentation. Several cultural conditions were examined to access their effect in optimizing enzyme production. The Rhizopus oryzae PR7 MTCC 9642 showed best growth at 28°C within a broad pH range of 6.0 to 10.0 with an optimal temperature and pH of isoamylase synthesis at 28°C and 8.0 respectively. Maximum growth and enzyme production was observed at 72 hours of cultivation, using carbon sources like carbon sources like starch, glycogen, amylopectin and dextrin of which dextrin acted as the best inducer for isoamylase synthesis. Tryptone was proved to be the best nitrogen source and addition of amino acids like Histidine HCl, Cysteine HCl and Tryptophan could remarkably enhance the enzyme synthesis .Amongst the additives thiol compounds like Dithiothreitol (DTT) and β-marcaptoethanol (B-ME) could increase enzyme synthesis. The strain could utilize native starch molecules from waste food stuffs, of which rice extract followed by bread dust showed best growth and isoamylase inducing activity.