A wastewater of a large metal processing plant of Hungary has a high concentration of various salts. The amount of sodium chloride is the highest, but the pH level is high as well. Parallel to this, the concentration of molybdenum is above the limit. For removing this valuable mineral we are developing an innovative procedure, which is using biotechnology to capture it. Since molybdenum is very useful especially for nitrogen fixing bacteria as well for plant’s nitrate reductase enzymes, the generated biomass is useful as biofertilizer.