Studies on Low-cost Substrates and Other Cultural Conditions for Optimal Amylase Yield from Aspergillus oryzae-SR2

The need for starch-converting enzymes in various industries has led to enormous interest in their production at a cheap rate. The present study was focused on the examination of various inexpensive substrates and other production parameters for amylase production by the most potential selected strain. It was observed that A. oryzae-SR2 was the best amylase producer (36.31±0.24 mm) among other Aspergillus isolates when screened by starch hydrolysis test. Preliminary submerged fermentation using soluble starch medium confirmed the potentials of A. oryzae-SR2 for amylase production. The maximum enzyme production under submerged fermentation was achieved with 0.5% sugar-cane juice supplemented with 0.5% dry-flakes fermented tapioca, 1% yeast extract, 7% inoculums concentration, pH 7.0, temperature of 55°C and incubation period of 48 h. The enzyme demonstrated strong hydrolytic activities (56.4%) on the tested starchy foods with cassava starch being the most hydrolyzed (101.5%) with 86.90±1.10% conversion efficiency at 70°C. The ability to produce high amount of amylase within a relatively short time (48 h) using cheap substrates and the ability of its enzyme to effectively hydrolyze starchy foods suggests its suitability for biotechnological application especially in starch-converting industries.