Abstract
Isopropanol-utilizing microorganisms were newly isolated from soils and several of them accumulated two acids in the culture broth, α-ketoglutaric acid being a major one and succinic acid a minor one. Two strains (N-79 and S-1), classified as the genus Mycobacterium, were examined for the cultural conditions with respect to the accumulation of the acids. The accumulation of α-ketoglutaric acid depended greatly on the pH value in the broth, which is required to be kept at around 4 for the maximum accumulation. By means of the pH-controlled culture (at 3.5) with a jar fermentor, strain N-79 accumulated a-ketoglutaric acid at a rate of 0.015g/liter/hr. The data obtained in this work indicate that the metabolism of isopropanol by strain N-79 probably proceeds via the acetone pathway without the interconversion between isopropanol and n-propanol.
