Mechanisms of bioleaching and the visualization of these by combined AFM & EFM

The understanding of mechanisms, by which microorganisms are effecting the dissolution of metal sulfides, what in general is called bioleaching, has progressed largely during the last 15 years. Whereas in the beginning of the nineties of the last century the direct and the indirect mechanisms were state of the knowledge, nowadays it is generally accepted that contact and non-contact mechanisms besides ferric iron, perhaps with some organic sulfhydryl groups, are the relevant players. Consequently, since the introduction of these ideas/hypotheses, research in this field has been revived considerably, as is obvious from the literature[2]. Also molecular biology has started to contribute to the understanding of these processes due to the clarification of the basic reactions