Minerals 2014, 4, 553-564; doi:10.3390/min4020553 OPEN ACCESS minerals ISSN 2075-163X www.mdpi.com/journal/minerals Article Chemoorganotrophic Bioleaching of Olivine for Nickel Recovery † Yi Wai Chiang 1,2,*, Rafael M. Santos 3, Aldo Van Audenaerde 3, Annick Monballiu 4, Tom Van Gerven 3 and Boudewijn Meesschaert 2,4 1 School of Engineering, University of Guelph, Guelph, ON N1G 2W1, Canada 2 Department of Microbial and Molecular Systems, KU Leuven, Leuven 3001, Belgium; E-Mail:
[email protected] 3 Department of Chemical Engineering, KU Leuven, Leuven 3001, Belgium; E-Mails:
[email protected] (R.M.S.);
[email protected] (A.V.A.);
[email protected] (T.V.G.) 4 Laboratory for Microbial and Biochemical Technology (Lab μBCT), KU Leuven @ Brugge-Oostende (Kulab), Oostende 8400, Belgium; E-Mail:
[email protected] * Author to whom correspondence should be addressed; E-Mail:
[email protected]; Tel.: +1-519-824-4120 (ext. 58217); Fax: +1-519-836-0227. † Note: Contents of this paper also appear in the conference proceedings of the MetSoc of CIM’s 7th International Hydrometallurgy Symposium, Victoria, BC, Canada, 22–25 June 2014. Received: 8 May 2014; in revised form: 11 June 2014 / Accepted: 12 June 2014 / Published: 20 June 2014 Abstract: Bioleaching of olivine, a natural nickel-containing magnesium-iron-silicate, was conducted by applying chemoorganotrophic bacteria and fungi. The tested fungus, Aspergillus niger, leached substantially more nickel from olivine than the tested bacterium, Paenibacillus mucilaginosus. Aspergillus niger also outperformed two other fungal species: Humicola grisae and Penicillium chrysogenum.