REGNVM PROKARYOTAE
Prokaryotes: unicellular microorganisms of 0.1-15 μm, presenting
rod or coccus shape, sometimes occuring filamentous or mycelial
forms. They are widely distributed in nature (soil, water, foods,
plants, animals, rarely hot springs or radioactive medium).
Cells have a single circular DNA chromosome, contained within a
region called the nucleoid & may also have various small circular
pieces of DNA (plasmids) inside the cell. The nucleoplasm is not
separated from the cytoplasm by a nuclear membrane.
Reproduction is most often asexual, through binary fission,
occasionally by budding. Cells may remain attached after division
resulting specific arrangements (strepto-, staphylo- etc.).
The cells are surrounded by a rigid peptidoglicans based wall with
the exception of the Mollicutes. The plasma membrane forms
vesicular, lamellar or tubular intrusions into the cytoplasm.
Respiratory and photosyntetic functions are associated with the
plasma membrane system (where available).
Ribosomes of the 70S type are dispersed in the cytoplasm.
Kingdom Prokaryotae includes Cyanobacteria (blue-green algae)
and Bacteria. The last makes the object of our pages.
Uncle Salm Salmonella isolation & identification scheme
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ABIS online Bacterial identification software. Free access
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