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[The ultrastructure of L-forms. III. The L-forms of S. typhi and Pr. vulgaris]
Abstract:
A marked polymorphism was revealed in the colonies of 5--7 day L-forms of S. typhi and Pr. vulgaris: among different types of the cells there prevailed spherical or oval forms with a distinct nucleoid. Three-layer cytoplasmic membranes--the site of formazan TNBT deposition in the reaction for succinic dehydrogenase--were detected on the greater part of the cell surface. Sometimes there were revealed on the surface of the membrane residues of the cell wall in the form of structureless material of low electron density or pieces of external membrane. Myelin-like structures, mesosomes of ring or lamellar structure and two-contour vesicles located directly in the cytoplasm were found in the cytoplasm. L-form cells displayed binary fission or reproduced by budding; in the latter case there formed elementary bodies surrounded by a three-layer membrane, not infrequently with a visible nucleoid and structures resembling mesosomes of the lamellar type.
Insights
Bacterial L-forms of Salmonella typhi and Proteus vulgaris exhibit significant cell polymorphism and unique reproductive methods. These include binary fission and budding, forming elementary bodies with distinct cellular structures.
Area of Science:
- Microbiology
- Cell Biology
Background:
- Bacterial L-forms are cell wall-deficient variants of bacteria.
- Understanding L-form morphology and reproduction is crucial for microbiology.
Purpose of the Study:
- To investigate the ultrastructure and reproductive mechanisms of S. typhi and Pr. vulgaris L-forms.
- To characterize the polymorphism and cellular components of these bacterial L-forms.
Main Methods:
- Transmission electron microscopy (TEM) was used to examine L-form cells.
- Enzyme histochemistry (succinic dehydrogenase activity) was employed to study cytoplasmic membranes.
Main Results:
- Marked polymorphism observed, with spherical/oval cells predominant and distinct nucleoids.
- Three-layer cytoplasmic membranes, sites of formazan TNBT deposition, were identified.
- Cellular structures including myelin-like formations, mesosomes, and vesicles were present.
- L-forms reproduced via binary fission and budding, forming elementary bodies.
Conclusions:
- S. typhi and Pr. vulgaris L-forms display diverse morphology and reproductive strategies.
- Ultrastructural analysis reveals complex internal and surface membrane structures.
- The findings contribute to the understanding of bacterial L-form biology and evolution.