A Study of the Effects of Physico-Chemical Factors on the Frequency of Plasmid Transduction by Bacteriophage RB49

T4-related bacteriophage RB49 is capable of general plasmid transduction with a relatively high frequency. Due to this mechanism, bacteria can acquire the ability to adapt to changing environmental conditions and explore new ecological niches. The effects of pH, temperature, and irradiation with long-wavelength ultraviolet light (λ = 366 nm) on the characteristics of the phage RB49 preparation containing transducing particles with pTurboGFP-B plasmid DNA and virulent particles with their own DNA were studied. Data on changes in the titer of virulent particles and the frequency of transduction of the pTurboGFP-B plasmid by the RB49 phage were obtained. After exposure to UV radiation for 2 h, the frequency of transduction of the pTurboGFP-B plasmid by the RB49 phage increased by ~3 times. After storing the preparation in ice for 40 min, a several-fold increase in the transduction frequency was observed. Based on the experimental data we obtained, it was assumed that the transducing particles of the RB49 phage may be more resistant to long-wavelength UV radiation and temperatures close to 0°C than virulent ones and provide the transduction process more efficiently than under normal conditions. Similar processes can occur in well-lit reservoirs, including cold ones, in which phages related to RB49 may occur. This indicates the possibility of more intensive horizontal gene transfer in aquatic ecotopes than previously assumed.