The Effect of Agitation on the Rate of Acid Formation by Lactobacillus delbrueckii *

The effect of agitation on tho rate of acid formation by the microaerophilic organism Lactobacillus delbrueckii was studied. Fermentations xwre conducted at constant temperaturo and pW, and with the continuous addition of a nutrilite source. The range of agitator speeds was from 85 t o 720 rev/min. The acid formation rate was found t o increase with increasing agitator speetIB and dcrrease with decreasing speeds if corn-steep liquor was tho nutrilite source. S o effect of agitation was observed with p a s t extract as the nutrilite source. The data from corn-stoep liquor modia were found to be consistent with a mass transfer mechanism, but did not u-arrant a conclusion as t o the specific nature of the effect of agitation. It was concluded, however, that the effect of agitation on thc acid formation rate was at most very small.