Electron Microscopy of the Cell Envelope of Ferrobacillus ferrooxidans Prepared by Freeze-Etching and Chemical Fixation Techniques

AUTOR(ES)

Remsen, Charles

RESUMO

Remsen, C. C. (Swiss Federation Institute of Technology, Zurich, Switzerland), and D. G. Lundgren. Electron microscopy of the cell envelope of Ferrobacillus ferrooxidans prepared by freeze-etching and chemical fixation techniques. J. Bacteriol. 92:1765–1771. 1966.—A comparison was made of the fine structure of the cell envelope of the gram-negative bacterium Ferrobacillus ferrooxidans when cells were prepared for microscopy by freeze-etching and chemical fixation techniques. Cell envelopes of chemically fixed cells appeared as five separate layers distinguishable by their location and electron density. Frozen-etched cells showed a three-layered complex with each layer measuring approximately 100 A in thickness. The latter technique is considered to be “artifact-free” and, as a technique, yields purely morphological information on the natural state. The three layers revealed by freeze-etching are: the outer layer, a lipoprotein-lipopolysaccharide layer; the middle layer, a layer composed of globular protein attached to fibrillar mucopeptide; and the innermost layer, the cytoplasmic membrane. The latter was covered with 100 to 120 A particles. The relationship of the aforementioned layers to those seen in chemically fixed cells is discussed.

Documentos Relacionados

• Scanning electron microscopy and freeze-etching of gonorrhoeal urethral exudate.
• Envelope of Mouse Mammary Tumor Virus Studied by Freeze-Etching and Freeze-Fracture Techniques
• Ultrastructure of the Cell Envelope of Escherichia coli B After Freeze-Etching
• Fine Structures of Cell Envelopes of Chlamydia Organisms as Revealed by Freeze-Etching and Negative Staining Techniques
• Morphology and Morphogenesis of Sindbis Virus as Seen with Freeze-Etching Techniques