Effects of low intensity electromagnetic irradiation of 70.6 and 73 GHz frequencies and antibiotics on energy-dependent proton and potassium ion transport by E. coli.
The effects of low intensity (flux capacity 0.06 mW/cm2) coherent electromagnetic irradiation (EMI) of 70.6 and 73 GHz frequencies and their combined effects with antibiotics--ceftriaxone or kanamycin (0.4 or 15 microM, correspondingly) on E. coli K12 growth and survival have been reported previously. To further study the effects of EMI and antibiotics and mechanisms, decrease in overall energy (glucose)-dependent H+ and K+ fluxes across the cell membrane was investigated in E. coli. The depression of H+ and K+ fluxes rate was maximally achieved with the 73 GHz frequency. The EMI strengthened the effect of N,N'-dicyclohexycarbodiimide (DCCD, an inhibitor of the F0F1-ATPase). The 73 GHz EMI had more influence on H+ efflux inhibition, whereas 70.6 GHz on K+ influx. Also, EMI strengthened the depressive effects of ceftriaxone and kanamycin on the overall and DCCD-inhibited H+ and K+ fluxes. The 73 GHz EMI strengthened the effect of ceftriaxone on both ions fluxes. Kanamycin depressed H+ efflux more as compared to ceftriaxone, which was also strengthened with EMI. The results of E. coli H+ and K+ transport systems activities depression by irradiation and the irradiation effect on DCCD and antibiotics action indicated the EMI and antibiotics causing primary changes in the bacterial membrane.