Table 1.

Glossary of Terms Used in the Paper

Epigenetic alterations	Inherited but revocable changes in the genome (without modification of DNA sequences) that lead to metastable changes in gene expression.
Restriction–modification system	Bacterial mechanism of defence against invasion by foreign DNA (for example, viruses). It is comprised of genes that encode a restriction enzyme and a modification methylase.
Histone Like Proteins (HLPs)	Proteins with non-specific DNA-binding activity that regulate gene expression in the bacterial genome by changes in DNA supercoiling and that play a role in a structural organization of the bacterial DNA.
Small RNAs (sRNA)	Small non-coding RNAs regulating gene expression at the level of transcription, translation, chromatin organisation by base-pairing with a target mRNA or DNA. In mammalian cells they include small nuclear RNAs (snoRNA), microRNAs (miRNA), and short interfering RNAs (siRNA/iRNA).
Cellular strategy	A set of cellular functions that are epigenetically fixed in the genome.
Stationary phase/state	A steady-state equilibrium at which the continuing cell division is balanced by the continuing cell death.
Sustained stress environment	Cellular environment leading to continuing cell death and, therefore, sustained generation of stress-induced survival and proliferative signaling in a subpopulation of the cells.
Epigenetic reprogramming	A set of epigenetic alterations in the genome that are induced by sustained changes in the cellular environment and that allow to implement a cellular strategy.
Stationary-state mutagenesis	The acquisition of beneficial mutations by bacteria in a growth-limited state.
Mutator phenotype	A cellular survival strategy induced by sustained stress environment and characterized by increased rate of mutations.
Stress-induced cellular adaptation	Epigenetic reprogramming of a subpopulation of cells in a sustained stress environment to implement the mutator phenotype.