关键词: 直流电, 电解刺激, Enterobacter dissolvens, 脱氢酶, 葡萄糖, 氧化还原电位

Abstract: Growth and metabolic behavior of E. dissolvens under the exposure to weak direct current (DC) was investigated by using glucose as the sole carbon source. When salt bridge electrodes were applied to shield the electrode reactions, the implementation of DC led to neglectable increases in cell growth and glucose uptake. According to the cyclic voltammogram of cell broth, water electrolysis was determined to be the main electrode reaction when DC was implemented via platinum electrodes. After 12 h electrolytic stimulation, the specific dehydrogenase activity and glucose consumption was 1.98 and 1.48 fold as much as that determined in the absence of electric field, respectively. These might be due to the generation of the hydrogen at cathode, which decreased the redox potential of culture solution and maintained a reductive environment even under aerobic condition. The enhanced cell growth could be seen as a result of increased glucose uptake under the application of DC. Accelerated cell death was also observed during the later stationary phase. Scanning electron microscopic observation showed that the cells after the growth phase were damaged by the DC application.

Key words: direct current, electrolytic stimulation, Enterobacter dissolvens, dehydrogenase activity, glucose, redox potential