Bioleaching experiments with a mixed Acidithiobacillm-culture were carried out in shake flasks as well as in column percolators with crushed and sieved sphalerite-rich ore from a former mine in the German Harz Mountains. Efficient sphalerite dissolution in the bioleaching assays was observed in contrast to the chemical leaching experiments. The redox potential was higher in the bioleaching than in the chemical control assays. Total cell counting and most-probable-number cultivation congruently exhibited high cell numbers at the end of the bioleaching experiments of about one month. The kinetics of sphalerite bioleaching showed a linear increase of the zinc concentration in solution with time and exhibited similar sphalerite surface related reaction rates for percolators and shake flasks indicating that the overall sphalerite dissolution rate was mainly controlled by the total mineral surface. Maximal zinc bioleaching efficiency with up to 10 g/L zinc in the pregnant leach solution was achieved at a low starting pH 1.8 and addition of 2 g/L ferrous iron. Besides zinc, up to 1 mg/L gallium as trace element was extracted. Electrochemical analysis of leaching residues was performed as well to analyze potential surface related limitations for metal sulfide dissolution.