Effect of agitation speed on the synthesis of Mucor miehei acid protease

Different experiments using Mucor miehei CBS 370.65 were carried out to study the effect of agitation speed on the production of the mold acid protease. The experiments were conducted in shake flasks at a fixed substrate concentration of 58 g l^?1 of total carbohydrates and at shaker speeds from 80 to 380 rev min^?1. Enzyme production was found to be directly proportional to the shaker speeds, with the highest concentration of enzyme of 1,400 Soxhlet Rennet units (SU) ml^?1 obtained at 380 rev min^?1. The yield of product to substrate at 380 rev min^?1 was determined to be 27,081.0 SU g^?1 substrate and the productivity of the process was 221 SU g^?1 h^?1. Enzyme production was partially growth associated, and glucose supported both cell growth and enzyme production. Product formation and cell concentration were directly related to the rate of substrate consumption. The rate of product formation decreased when product started to accumulate, suggesting that the process was affected by feedback repression.