AN EXTRACELLULAR MATERIAL ELABORATED BY MICROCOCCUS SODONENSIS

Abstract

Campbell , J. N. (American Meat Institute Foundation, Chicago, Ill.), James B. Evans Jerome J. Perry, and C. F. Niven, Jr. An extracellular material elaborated by Micrococcus sodonensis . J. Bacteriol. 82: 828–837. 1961.—When actively growing in a yeast extract-tryptone broth, Micrococcus sodonensis produced rather large quantities of an extracellular material. On a dry weight basis, this material consisted of approximately 80% deoxyribonucleic acid (DNA), 6% ribonucleic acid, 13% protein, and a small quantity of a cell pigment which contained an associated iron porphyrinlike compound. The extracellular material was not produced in other complex or synthetic media. Removal of cells from the appropriate growth medium and suspension in distilled water resulted in the prevention of formation of the material if it had not already begun, or its immediate cessation in those cells which had been actively producing the material. Cells producing the extracellular material exhibited an increasingly higher concentration of intracellular DNA as incubation proceeded, whereas cells growing under conditions not supporting such production showed a decline in intracellular DNA as the culture aged. A similar increase of intracellular DNA, but not release of extracellular material, could be effected by addition of yeast extract or high levels of purine compounds to a medium which did not support the production of extracellular material. The base composition and ratios of both extracellular and intracellular DNA produced under all conditions tested were compared and found to be similar or identical, and to correspond to the classical Watson-Crick structure for DNA.