Abstract:The single-chamber bioelectric reactor was used to study effect of direct current on growth of Acidithiobacillus ferrooxidans (A. ferrooxidans). The experimental results show that when current intensity is 10 mA, the ferrous oxidation rate of A. ferrooxidans rises by 33.15%, and appropriate current stimulation can maintain the activity and growth rate of bacterial cells more stable. The results of morphological analysis of bacterial cells under the action of electric field shows that appropriate current stimulation can make cells generate higher transmembrane potential, change the permeability of cell membrane, pump more Fe2+ into the inner membrane, and promote A. ferrooxidans growth and reproduction.