Abstract

The cultural and nutrient requirements of Aspergillus niger for production of α-amylase in production media containing different pH, temperature, incubation period, metal ion concentrations, surfactants, carbon sources and nitrogen sources were quantified in present study. The optimum pH, temperature and incubation period for enzyme production were 5.0, 30°C and 5th day, respectively. Of the carbon sources, starch at 0.5% was recorded to be the best carbon source for enzyme production. Peptone at 0.03% was ideal nitrogen source. However, surfactants Tween-80, Triton X-100 and Sodium dodecyl sulphate at 0.02, 0.002 and 0.0002% concentration were most effective for enhancement of α-amylase production. The main objectives of the present study were to use a suitable fungal strain for production of extra cellular alpha-amylase, to determine the time course for the production of alpha-amylase and to study the effects of external substances that may enhance the production of extra cellular alpha-amylase, including metal ions and surfactants.