LAUSR

Abstract—Modern ideas about the world of microorganisms have been developed mainly due to the studies at the population level. Such an approach was justified by the need to overcome the limitations in the sensitivity of the physicochemical, molecular biological, and genetic methods used. The potential differences between individual cells were therefore leveled, the properties of all cells were averaged, and the obtained data characterized the studied microbial populations as a whole. Over time, some analytical methods have been improved to such an extent that the prospect of quantitatively exploring many physicochemical and morphological properties of individual microbial cells has been opened up. This allowed taking a new approach to solving a number of problems, including the heterogeneity of microbial populations, the nature of the microorganisms unculturable in laboratory conditions and of persistent states, the development of biofilms, the interaction of microorganisms with plant and animal cells, the relationship of structure and function in metabolism, and a number of others. This review briefly describes the main methods of quantitative analysis of single bacterial and yeast cells at the cellular and subcellular levels and presents examples of their use according to the literature for the last fifteen years.