Effects of elevated pressures on the activity of acidophilic bioleaching microorganisms

Réka Hajdu-Rahkama, Sarita Ahoranta, Aino-Maija Lakaniemi, Jaakko A. Puhakka

Research output: Contribution to journalArticleScientificpeer-review

2 Citations (Scopus)
1 Downloads (Pure)


This study reports effects of elevated pressures on the oxidation of a soluble ferrous iron and low-grade sulphidic ore as little is known about biological iron and sulphur oxidation under these conditions. Pressure effects were studied in a pressurised batch-operated stirred tank reactor using acidophilic enrichment cultures. The oxidation of soluble Fe2+ by enrichment culture dominated by Leptospirillum ferriphilum, Sulfobacillus sp. and Ferrimicrobium acidiphilum increased with increasing pressure induced by technical air to up to +3 bar (0.63 bar PO2) and was inhibited at +7 bar (1.47 bar PO2). Elevated pressures induced by nitrogen (low oxygen partial pressure) were tolerated up to +40 bar. Another enrichment culture dominated by Acidithiobacillus ferrivorans, Sulfobacillus sp. and F. acidiphilum partially oxidised the ore at pressures up to +20 bar induced with air (4.2 bar PO2). This is the first study reporting activity of acidophiles under pressurised conditions in a stirred tank reactor.

Original languageEnglish
Article number107286
JournalBiochemical Engineering Journal
Publication statusPublished - 15 Oct 2019
Publication typeA1 Journal article-refereed


  • Acidophiles
  • Biooxidation
  • Iron oxidation
  • Pressure tolerance
  • Pressurised stirred tank reactor

Publication forum classification

  • Publication forum level 1

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Environmental Engineering
  • Biomedical Engineering


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