Spheroplasts of the photosynthetic bacterium Rhodospirillum rubrum were prepared from cultures grown in either the presence or absence of light. Cells were converted into spheroplasts by using lysozyme and Versene and fixed in a sucrose-veronal-acetate buffer mixture containing osmium tetroxide. Some preparations were shadow-cast and examined whole; others were embedded in Epon 812 and sectioned. The action of lysozyme and Versene appears to result in removal of the cell wall in strips. The relationship of the chromatophores to the cytoplasmic membrane is readily visualized in sections of broken spheroplasts, and in areas the chromatophores are seen to be continuous with the membrane. In all preparations examined, no definite connections between individual chromatophores were observed. In some cells large spherical granules were evident which either possessed or lacked a clearly visible limiting membrane. On serial sectioning, all granules appeared bounded by a single membrane 40 A wide. The granule membrane was well defined only if the section came from the center of the granule. Sections at other levels showed either a diffuse membrane or no membrane at all. The reasons for this are discussed.
Article| February 01 1964
OBSERVATIONS ON THE FINE STRUCTURE OF SPHEROPLASTS OF RHODOSPIRILLUM RUBRUM
E. S. Boatman
From the Departments of Microbiology and Preventive Medicine, University of Washington, Seattle.
Mr. Boatman's present address is at the Department of Preventive Medicine
Received: May 21 1963
Online ISSN: 1540-8140
Print ISSN: 0021-9525
Copyright © 1964 by The Rockefeller Institute Press
E. S. Boatman; OBSERVATIONS ON THE FINE STRUCTURE OF SPHEROPLASTS OF RHODOSPIRILLUM RUBRUM . J Cell Biol 1 February 1964; 20 (2): 297–311. doi: https://doi.org/10.1083/jcb.20.2.297
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