The revolution in information and communication technology has brought huge technical benefits and wealth, but has created a major global problem: the generation of vast amounts of electronic waste, or e-waste through product obsolesce. The challenge in managing e-waste will be in developing sustainable recycling technologies that are able to address the volume and complexity of this waste using cost effective and ecologically sensitive methods. In this study, the capability of microorganism metabolic acids in dissolving the metallic fractions from waste printed circuit boards was examined. Several factors were considered in the examination of the activity of the acids including secondary reactions, solution pH, temperature and the nature of ligands in solutions (or bio-acid constituents). The leaching tests were conducted ex-situ, using synthetic organic acids. Leaching was performed for periods of up to 6 h at 70-90 degrees C and 1000 r.min(-1).