RESPONSE OF PLANTS AND SOIL MICROORGANISMS TO EXTREMELY LOW FREQUENCY ELECTRIC FIELDS

摘要

Potential sublethal direct effects of an applied electric stress on microorganisms were evaluated employ¬ing a 14C-substrate uptake approach. The uptake proce¬dures were taken from published sources and modified to fit out experimental constraints. The application of the electric stress was carried out through the use of specially designed electrical circuitry and precision equipment. A compromise was made between the biological methods and the electrical scheme so that any indirect variables due to the electrical stress, such as Joulean heat production or chemical changes in the medium, could be eliminated or accounted for.nNo statistical variation was shown for the effects of an electric field on organic C uptake for either pure cultures of Citrobacter freundii or mixed populations of indigenous soil microorganisms. The electric field strengths utilized were 10 volts meter-1 and 50 volts meter-1.