The enzymes which are concerned in the decomposition of glucose and mannitol by Bacillus coli communis

Abstract

By the cultivation of bacteria in the presence of certain substances, for the most part toxic in character, it is possible to obtain strains in which the fermentative powers differ considerably from those of the parent organisms. As an example may be taken a variety of B. coli communis (Escherich) which was produced by the growth of that organism on agar containing sodium chloroacetate (see Penfold, 1911). This strain differed from the parent strain in that it now decomposed glucose with the production of acid but not of gas. This result pointed to two possibilities ; firstly the decomposition of glucose by the selected strain might be brought about by a set of ferments, which acted very differently from those of the normal strain responsible for the decomposition of the same substance, or secondly the primary cleavage products of glucose might be the same both from the original and the selected strain, and the difference between the action of the two might depend upon some secondary process, as for example the decomposition of formic acid, through which, as Pakes and Jollyman (1901) and Harden (1901) have shown, the carbon dioxide and hydrogen most probably arise.