Аннотация:DNA is organized in the nucleoid of an actively growing cell hierarchically with three levels of DNA compaction: The lower level (small scale ≥ 1 kb bp) is provided by interaction with histone-like NAP proteins. Actively growing cells maintain a dynamic, far from equilibrium order through metabolism. When cells enter a dormant state (practically complete absence of metabolism), the usual biochemical methods of protecting DNA cease to work, and cells, adapting to new conditions, are forced to use the physical mechanisms of DNA protection. The structure of DNA in the nucleoid of dormant cells formed under starvation stress was studied using synchrotron radiation diffraction and transmission electron microscopy (TEM). The experimental results made it possible to visualize the structures of the lower hierarchical level of DNA compaction in the nucleoid of dormant cells. A series of diffraction experiments performed for the first time indicates the presence of a periodic ordered organization of DNA in all studied bacteria. TEM made it possible to extract fine visual information about the type of DNA condensation in the nucleoid of the bacterium Escherichia coli. Intracellular nanocrystalline, liquid-crystalline and folded nucleosome-like structures of DNA have been found. The folded nucleosome-like structure was observed for the first time and is the result of multiple folding of long DNA molecules around the Dps protein and its associates. The different types of DNA condensed state found by us in the studied dormant E. coli cells (DNA condensation heterogeneity) provide additional arguments in favor of the concept that considers a microbial population as a multicellular organism. The study of changes in DNA architecture under the influence of the chemical analogue of the autoinducer of anabiosis 4-hexylresorcinol (4HR) was studied. An increase in the 4GR concentration induces the transition of a part of the cells of the population to an anabiotic dormant state, and then to a mummified state. The studies of the DNA structure in the anabiotic and mummified states show the spectroscopic identity of the DNA structure in the dormant anabiotic state and in the dormant state formed during starvation stress. Studies of the structure of DNA in the mummified state show a strong difference from the structure of DNA in the anabiotic state.