Electrolytic Stimulation of Escherichia coli by a Direct Current

Abstract:

Growth behavior of Escherichia coli (E. coli) under the exposure to direct current (DC) was studied in this paper, with electrolytic stimulation on the culture flask of E. coli using gauze titanium and platinum electrodes. The electric field-activated mechanism was also investigated by cyclic voltammestry technique, constant direct current technique, SDS-PAGE as well as enzyme activity assay of ATPase. The results show that direct current can promote the growth of E. coli under the current density of 0.2275 mA/cm2, and the growth speed is gradually accelerated with increasing current density, but 0.0455 mA/cm2 is the optimal current density to obtain the maximum viable cells. When the same current density electric field is applied to Pt electrodes and Ti electrodes, the Pt electrode culture system is superior to Ti electrode culture system. The cathode electrolysis products of water are the primary factor for the difference, which include adsorbed hydrogen and H2. It is also found that the 0.091 mA/cm2 direct current can promote ATPase activity effectively, with 3.2 times at most after 8 hours. Bacterial proteins about 25 kD and 35 kD are expressed higher while proteins of 66.2 kD are expressed lower after (under) electrolytic stimulation of 0.0455 mA/cm2 direct current.