(Recent book "Recent Biotechnological Applications in India,Eds-S. C. Santra and A. Mallick, March 2016)

Biomining is defined as the technologies that utilize microbial community for the extraction of metals from its ore or wastes and facilitate a greener recovery. Extraction of manganese by biomining is now a thing of the present and not just a hypothesis, as it was few decades back. The severe industrial importance of manganese has led to augmented global production of manganese in the last few years which has led to a decrease in the amount of high grade ores. It has also resulted in pollution of both terrestrial and aquatic ecosystems due to the generation of massive amounts of manganese containing wastes. Therefore, biomining is now being employed to recover manganese low grade ores and solid mining wastes which serve a dual purpose of both resource recycling and bioremediation. Manganese bio recovery can be accomplished by a wide range of bacterial and fungal strains capable of growing under diverse environmental conditions. They solubilise manganese by direct and indirect mechanisms thereby aiding its recovery. Bacterial solubilisation is mainly carried out by direct mechanism which involves the direct contact of the cell with the metal. However fungal solubilisation is mostly correlated with indirect mechanism which does not require direct contact of the cells with metal particles and involves solubilisation by the help of bio generated metabolites that mainly includes organic acids. Many enzymes like Muilticopper oxidase, Manganese reductase and Peptidyl-prolyl-cis-trans isomerise have been linked to manganese solubilisation. The present scenario of commercial manganese recovery through booming is very encouraging and this technology holds immense potential for future metal recovery and bioremediation endeavours.