| Abstract: | The ultrastructure of microbial cells was studied in situ in natural biotopes by high-resolution transmission electron microscopy using the known methods of cryofractography, thin sectioning, and the negative staining of total cell specimens, as well as new methods of the low-temperature fractionation of microbial cells (providing for the recovery of cells from natural sources and their concentration), the preparation of micromonoliths, and aimed electron microscopy. Among the natural biotopes studied were permafrost ground and oil sludge. Most of the microorganisms found in the 1- to 3-million-year-old permafrost ground represented resting forms (spores, cysts, and cyst-like cells with specific organo-mineral envelopes). Oil sludge older than 35 years contained bacteria of atypical morphology and ultrastructure, including various resting forms and ultramicrobacteria. The data obtained is indicative of considerable promise of high-resolution electron microscopy in studying microbial communities in situ. |
