History of Science and Engineering Annotation << Back THE ROLE OF SURFACE AND EXOCELLULAR STRUCTURES OF MICROORGANISMS IN THEIR ADAPTATION TO EXTREME ENVIRONMENTS V.V. Dmitriev, A.N. Zvonarev, T.G. Rusakova To study the structural and functional changes occurring in microorganisms (yeast and bacteria) when they adapt to extreme conditions, a complex approach has been developed that combines methods of electron and light microscopy with biochemical analyses. The studies were carried out at the level of individual cells, populations, and communities placed in media supplied with hard-to-utilize carbon substrates (such as oil hydrocarbons, synthetic surfactants, and solid substrates) or toxic substances (heavy metals, petroleum products, etc.) or those that survived under conditions of starvation, extremely long exposure to cold (permafrost) or high temperatures (hot springs of Kamchatka). All the studied microbial cells underwent significant changes in their surface and exocellular components allowing them to survive under extreme conditions. They are the formation of canals in the cell wall, specific invaginations in the cytoplasmic membrane, extracellular fibrillar polymer structures, and others. The results of studies of adaptive reactions in lower eukaryotes (by example of yeast, as a model) can help to solve some biotechnological problems, reveal mechanisms of the development of pathological processes in humans and mammals and to find the ways of their inhibition at the cellular level. Keywords: yeast, bacteria, extreme factors, ultrastructure, adaptation, hardly utilizable substrates, exocellular components, trophosomes, permafrost. DOI: 10.25791/intstg.12.2020.1245 Pp. 30-43.