Effect of fermentation conditions on toxin production by Clostridium botulinum type B

Abstract

To obtain high yields of toxin for the preparation of purified neurotoxoids, the authors examined the time of appearance and the quantity of toxin produced by the Bean strain of C. botulinum type B under various conditions by using a fermentor system. The medium employed consisted of 2.0% casein hydrolysate and 1.5% yeast extract plus an appropriate concentration of glucose. The maximum toxin concentration (4 x 105 to 5 x 105 mouse median lethal doses per ml) was attained within 48 h under the following fermentation conditions: an initial glucose concentration of 0.5 or 1.0%, a temperature of 35°C, a nitrogen overlay at a rate of 5 liters/min, and an agitation rate of 50 rpm.