Biotechnology Letters

, Volume 24, Issue 23, pp 2011–2016 | Cite as

Toxicity of flotation reagents to moderately thermophilic bioleaching microorganisms

  • Naoko Okibe
  • D. Barrie Johnson


The toxicity of 15 flotation reagents (including xanthates, carbamates, thiophosphates, a mercaptobenzthiazole and a frothing reagent) used for concentrating sulfide minerals to five species of mineral-oxidising, moderately thermophilic and acidophilic microorganisms was assessed. The acidophiles tested included four bacteria (a Leptospirillum isolate, Acidimicrobium ferrooxidans, Acidithiobacillus caldus and a Sulfobacillusisolate) and one archaeon (a Ferroplasma isolate). There was wide variation both in terms of the relative toxicities of the different flotation reagents and the sensitivities of the microorganisms tested. In general, the dithiophosphates and the mercaptobenzothiol were the most toxic, while the Leptospirillum and Ferroplasma isolates were the most sensitive of the acidophilic microorganisms. The significance of these findings, in view of the expanding application of ore concentrates bioprocessing, is discussed.

acidophiles biomining flotation reagents mineral leaching moderate thermophiles 


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Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • Naoko Okibe
    • 1
  • D. Barrie Johnson
    • 1
  1. 1.School of Biological SciencesUniversity of WalesBangorUK

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