Handling stress; survival and growth strategies of acidophiles

Acid mine drainages are toxic water streams with very low pH and high heavy metal concentrations which result from mining activities. This study investigates acidophilic sulfate-reducing bacteria that handle these extreme conditions and can reverse this phenomenon.


Industrial mining activities and the natural exposure of metallic sulfide-ores to water and oxygen produce sulfate-rich waters, termed acid mine drainage or acid rock drainage, respectively. Characterized by their low pH (<3) and high heavy metal concentrations, these water streams have a detrimental environmental and economic impact and pose an extreme environment for organisms.


This research will investigate microbial isolates with important physiological properties in the carbon, sulfur and nitrogen cycles in these environments. Insights in their ecophysiology and (novel) coping mechanisms for toxic agents found in this extreme environment will give fundamental knowledge of survival strategies employed by microorganisms and the microbiology of acid mine drainage environments as a whole. Knowledge gained can be used for the optimization of bioremediation techniques and the development of novel biotechnological applications.

Techniques involved

The project focusses initially on a recently isolated acidophilic sulfate-reducing bacteria. In reactor cultivations and flask cultivations the stress mechanisms under non-stressed and maximum tolerated concentrations will be assessed. Subsequently gene expression will be studied via transcriptomics and proteomics. Furthermore the dissimilatory nitrate reduction pathway of this organism is also studied using transcriptomics and potentially anaerobic enzyme purification and characterisation.

Key techniques

  • Anaerobic microbiology
  • Reactor operations
  • Transcriptomics
  • Genomics
  • Proteomics


Are you interested in this project? Please contact Reinier Egas.