Effect of pH, temperature, nitrogen source and glucose concentrations on acid protease production by Aspergillus niger mutant

A study was made of the effect of pH of medium (3.0-8.0), temp. of incubation (20-45°C), N source (inorganic or organic), and glucose concn. in the medium (0.05-3.0%) on acid protease production by Asp. niger in a medium containing 4% wheat flour. A study was also made of protease production on different media (wheat, moong, mash, gram, masur + jowar, soybean, barley, bajra), wheat giving the best results. Max. enzyme production was achieved under the following conditions: initial pH of 7, incubation temp. of 35°C, and nitrate as N source. Addition of glucose to the medium enhanced mycelial growth but had an adverse effect on enzyme production