Chemical action of Bacillus lactis aerogenes (Escherich) on glucose and mannitol : production of 2 : 3-butyleneglycol and acetylmethylcarbinol

Abstract

In the course of an investigation on the chemical action on glucose of the lactose-fermenting bacteria of faces it was found that, whereas B. coli communis yields, with glucose, acetic acid and alcohol in approximately equal molecular proportions, B. lactis aerogenes produces a much smaller amount of acetic acid, relatively both to the alcohol and to the sugar fermented. It was, moreever, previously known that B. lactis aerogenes produces a greater volume of gas, containing a larger proportion of carbon dioxide than does B. coli communis . These facts indicate that the fermentation of glucose by this organism is of a different type from that brought about by the B. coli communis . A detailed examination of the products was therefore made. For this purpose the organism was grown anaerobically in a medium containing 1 per cent. of Witte peptone and 2 per cent. of pure glucose in the presence of chalk, the method of collecting the gases evolved and of examining the products being the same as that previously employed in the investigation of the action of B. coli communis on glucose.§ All the substances produced by B. coli communis from glucose were again found, viz., lactic acid, acetic acid, succinic acid, formic acid, ethyl alcohol, carbon dioxide, and hydrogen. A quantiative estimation, however, revealed the fact that only about two-thirds of the carbon of the glucose was thus accounted for. This is shown in the following tables, which embody the results of three separate estimations (Cols. 1, 2, 3), Table I giving the actual percentages by weight on the sugar fermented of the various substances produced, and table II the number of carbon atoms per molecule of sugar decomposed represented by each product. The results of a typical fermentation of glucose by B. coli communis are added (Col. 4) for the sake of comparison :─