THE CORRELATION OF VARIATION IN DYE SENSITIVITY WITH GRAM CHARACTER IN CERTAIN GRAM-POSITIVE ORGANISMS

Abstract

Chance variants of Gram-positive organisms discovered in culture media containing gentian violet were found to exhibit only a very gradual subsequent change. By long subculturing under a constant set of conditions the variant tendency may be increased, while under another constant set of conditions a tendency to an extremely slow reversion to the original strain is noted. Loss of Gram-positiveness has been shown to parallel exactly the decrease in sensitiveness to basic dye. Loss of Gram-positiveness has been shown to be accompanied by a shift in the isoelectric range of the organism. Single-cell cultures obtained by use of a modified Orskov technic were used in these studies.