Epigenetic Mechanisms of Gene Expression Regulation in Bacteria of the Genus Bacillus

Rapid development of molecular genetic technologies made it possible to analyze in detail the phenomena that can be attributed to epigenetics, i.e., phenotypic switches in bacterial cell cultures. Phenotypic changes against the background of an unchanged genome can be a temporary reaction to external factors and disappear with the change of conditions or can be caused by cell differentiation and maintained regardless of external factors. In the literature, extremely heterogeneous terminology with synonymous terms for these phenomena is used, depending on their characteristics (bistability, specialization, hysteresis, phase variation, dissociation). One of the objectives of this review is to systematize the terminology used. Representatives of the genus Bacillus were selected as an object of analysis, since they exhibit a considerable number of epigenetic phenomena. In addition, bistability is an important factor affecting the efficiency of using bacteria of the genus Bacillus in biotechnological processes. The study provides a brief overview of epigenetic switches in the genus Bacillus, their mechanisms, methods of detection and analysis, and possible evolutionary and ecological role, as well as practical applications.