The Effect of high hydrostatic pressure on the viability and mutagenesis of Salmonella typhimurium

© 2017, Pleiades Publishing, Ltd. This work is devoted to the study of the influence of high hydrostatic pressure (HHP) on the viability and level of mutagenesis of Salmonella typhimurium. It was established that the viability of bacteria significantly decreases under hydrostatic pressure of 200 MPa or higher. In addition, the viability index of the bacteria is six orders of magnitude lower with respect to the number of colony-forming units (CFUs) compared to the data of the flow cytofluorometry analysis. This is probably due to the transition of some part of the bacterial population to a viable but nonculturable state (VBNC). HHP of 50 MPa caused a 1.9-fold increase in the number of His + revertants of the S. typhimurium strain TA98, which indicates the potential of the induction of gene mutations under these conditions. The mechanisms to reduce the viability and genetic changes in bacterial cells under HHP conditions are discussed