Abstract
Potassium either as potassium chloride or dipotassium hydrogen phosphate was found to stimulate production of 2,3-butanediol from starch by Bacillus polymyxa and to increase the diol: ethanol ratio. In a casein hydrolysate medium, potassium alone produced this effect; however, in a synthetic (amino acid) medium, phosphorus was found to cause a slight increase in yield of diol especially in the presence of potassium.Potassium, phosphorus, and magnesium were shown to be required for growth of B. polymyxa in a synthetic medium containing glucose, amino acids, and biotin.By means of 'resting cells' of B. polymyxa, acting on glucose, it was demonstrated that potassium specifically stimulated the diol-synthesizing mechanism and that sodium could replace this element partially.