NUCLEI AND LARGE BODIES OF LUMINOUS BACTERIA IN RELATION TO SALT CONCENTRATION, OSMOTIC PRESSURE, TEMPERATURE, AND URETHANE

Abstract

Using Robinow''s osmic fixation, HC1 hydrolysis and Giemsa staining methods, the nuclear structures in young cultures of Photobacterium phosphoreum and Achromobacter fischeri were investigated The chromatin in the coccoid cells of the former species resembled in appearance various stages of mitotic cell division. In the latter species, the chromatin normally occurred as small granules which appeared to aggregate or coalesce, accompanied by denser staining, under the influence of concentrated NaCl, but to disperse, with decreased stainability, under the influence of dilute NaCl or of isotonic sucrose. These changes were reversible. In very dilute NaCl, irreversible osmotic cytolysis occurred leaving no evidence of nuclear structures. Brief incubation at above-optimum temps., or in the presence of 0.5 unspecified urethane at room temp., caused a coalescence or pyknosis of the chromatin. "Large bodies," many times the size of the ordinary cells, and containing chromatin in various arrangements, usually developed from some of the small cells in cultures of 1-6 hours incubation.