The Confluence of Heavy Metal Biooxidation and Heavy Metal Resistance: Implications for Bioleaching by Extreme Thermoacidophiles

Minerals

Garrett Wheaton²  James Counts²  Arpan Mukherjee¹  Jessica Kruh²  Robert Kelly¹ 

[1] Department of Chemical and Biomolecular Engineering, North Carolina State University, EB-1, 911 Partners Way, Raleigh, NC 27695-7905, USA;

关键词: extreme thermoacidophiles;    bioleaching;    heavy metal resistance;    heavy metal biooxidation;    archaea;   

DOI  :  10.3390/min5030397

来源: mdpi

【 摘 要 】

Extreme thermoacidophiles (T_opt > 65 °C, pH_opt < 3.5) inhabit unique environments fraught with challenges, including extremely high temperatures, low pH, as well as high levels of soluble metal species. In fact, certain members of this group thrive by metabolizing heavy metals, creating a dynamic equilibrium between biooxidation to meet bioenergetic needs and mechanisms for tolerating and resisting the toxic effects of solubilized metals. Extremely thermoacidophilic archaea dominate bioleaching operations at elevated temperatures and have been considered for processing certain mineral types (e.g., chalcopyrite), some of which are recalcitrant to their mesophilic counterparts. A key issue to consider, in addition to temperature and pH, is the extent to which solid phase heavy metals are solubilized and the concomitant impact of these mobilized metals on the microorganism’s growth physiology. Here, extreme thermoacidophiles are examined from the perspectives of biodiversity, heavy metal biooxidation, metal resistance mechanisms, microbe-solid interactions, and application of these archaea in biomining operations.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.