1986 Volume 32 Issue 2 Pages 137-147
Sixteen bacterial strains that utilize cholesterol as sole carbon and energy sources were isolated from food of animal origins such as butter, bacon, pork fat, and chicken fat. Morphological, biochemical, physiological, and chemotaxonomic characteristics including cell wall chemotype, cellular fatty acid composition, DNA base composition, and DNA homologies revealed that these isolates belonged to the genus Rhodococcus Zopf. Most of them were identified as Rhodococcus erythropolis (Gray and Thornton) Goodfellow and Alderson and Rhodococcus equi (Magnusson) Goodfellow and Alderson. The cholesterol-degrading ability and extracellular and intracellular cholesterol oxidase activities of these strains were compared with those of related bacteria. Most of the authentic Rhodococcus strains degrade cholesterol. However, the amount of the enzyme varied among the strains, and some isolates produced large amounts of extracellular cholesterol oxidase.