Studies on the production of bacterial rennet in a pilot plant fermentor

An attempt was made to find out the optimum aeration and agitation rates on the production of bacterial rennet from Bacillus sublilis K-26 using 5% wheat bran medium in a 13 liter fermentor. The enzyme activity and the growth rate were shown to increase with an increase in the rate of agitation. The fermentation experiments carried out at an agitation rate of 400 rpm showed an approximate threefold increase in enzyme activity with a considerable decrease in the fermentation time over those agitated at 200 and 300 rpm. The beneficial effect of a higher oxygen rate was observed for enzyme production occurring at a lower agitation rate. The inoculum activity and the varying amounts of antifoam agent which were added showed no apparent effect either on the total incubation time or on the final enzyme activity. It has been suggested that an agitation rate of 400 rpm with an aeration level of 3000 cc/min are the optimum values for the efficient production of bacterial rennet from B. subtilis K-26 using 5% wheat bran medium in a 13 liter fermentor.