F. Ayhan et al., The effect of fermentation parameters on the production of Mucor miehei acid protease in a chemically defined medium, J CHEM TECH, 76(2), 2001, pp. 153-160
Batch shake flask experiments were carried out with a fungal strain of Muco
r miehei ATCC 3420 to study the effects of five fermentation parameters; in
itial D-glucose concentration, temperature, initial pH, agitation rate and
inoculum ratio, on the production of rennin in a chemically defined medium.
A statistical design was used to assign the experimental levels of five fe
rmentation parameters for the determination of optimum conditions. The high
est concentration of midi-clotting activity (MCA) obtained was 2286 SU cm(-
3) (without concentration of the broth) at 29.6 g dm(-3) initial D-glucose
concentration, 6.8 initial pH, 37.6 degreesC temperature, 81 stroke per min
agitation rate and 5.2% (v/v) inoculum ratio. Although enzyme secretion wa
s a function of all the operational parameters investigated, the pH range (
4.6-5.2) reached at the time of enzyme production had a profound effect on
milk-clotting activity levels. In the fermentation sample at maximum milli-
clotting activity the R factor, the ratio of milk-clotting activity to prot
eolytic activity, was determined as 1 SU PU-1, denoting similar characteris
tics to a commercial animal rennet. (C) 2001 Society of Chemical Industry.