Studies on Energy Supply for Genetic Processes

In this study the hypothesis considering the involvement of the transmembraneous electrochemical gradient of protons () in the transport of DNA through the membrane of Bacillus subtilis cell during the initial stages of genetic transformation was verified experimentally. The value of the membrane potential of 100–140 mV (minus inside) was calculated from the data of K + distribution across the valinomycin‐treated cell membrane. The treatment of cells with protono‐phoreous uncouplers of oxidative phosphorylation during the exposure of transforming DNA to competent cells led to inhibition of the initial stages of genetic transformation without a detectable effect on the intracellular ATP concentration. The effects of uncouplers on the genetic transformation correlated with their effects on the value of the membrane potential. The dissipation of by K + and H + fluxes catalyzed by a mixture of valinomycin and nigericin led to the inhibition of the intial stages of transformation. The inhibitory effect of valinomycin was potentiated by nigericin at low concentration and vice versa. The same efficiency of genetic transformation in the presence of either phosphate or arsenate was observed in a modified Spizizen's medium. Genetic transformation in arsenate‐containing medium preceded despite the decrease of the ATP level in the cell population. This pattern of inhibitory effects supports the concept of being involved in the process of DNA transport in the initial stages of genetic transformation.