Oxidative assimilation by Bacillus subtilis.

It is a common observation that the oxidation of many substrates is not carried to completion by various species of microorganisms and that instead a portion of the substrate is assimilated by the cells. In those species possessing a high level of endogenous respiration and in which the rate of respiration is not increased markedly following the addition of a utilizable substrate, oxygen consumptions greater than the theoretical amounts for complete combustion are observed frequently before the rate of respiration levels off to near that of the endogenous control. We have observed this behavior repeatedly with species of the genera Bacillus and Mycobacterium. This paper summarizes observations on oxidative assimilation by a strain of Bacillus subtilis which consumed with different substrates amounts of oxygen ranging from less than 100 per cent of the amounts required for complete combustion to percentages over 200.