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The technology of microbial leaching exploits the interactions between microorganisms and minerals. Worldwide, about 25 % of copper, 10 % of uranium, 3 % of cobalt and nickel, and more than 10 % of the gold production is performed by microbial leaching. Intense research is under way in order to replace pyrometallurgical processes by biotechnology. Also, reclaimation of precious metals from wastes such as discarded electronics components can be performed by this technology. Microbial leaching can be employed to clean up environmentally undesirable remains from mining, providing the potential to reclaim precious metals. Such processes are still mainly empirically optimized and hold a great potential for systematic scientific optimization. On the other hand, uncontrolled microbial leaching such as encountered in “acid rock drainage” (ARD) represents a major problem in mining areas, leading to serious contaminations of soil, surface- and groundwater by heavy metals which are mobilized by the acids of microbial origin. In the former East Germany, vast areas have been contaminated by such processes, leading to an acidification of lakes down to a pH value of 2 with concomitant extensive contamination with heavy metals.

Biofilms can influence the kinetics of corrosion processes of metals, mineral and polymeric materials (“biocorrosion” or “microbially influenced corrosion” = MIC). It is estimated that corrosion damage, calculated as maintenance efforts, amount to about 12 billion DM per year, of which 10 - 20 % is considered to be microbially influenced. Intense and systematic research is required in order to detect, avoid and/or mitigate such damage and to define biocorrosion-resistant materials. Detailed knowledge of the behaviour of microorganisms at interfaces and the occurring biotic and abiotic processes as well as materials science is necessary in order to improve the situation. The focus of the Department of Aquatic Biotechnology will be:

Optimization (or prevention) of microbial leaching

  • Identification and characterization of the relevant leaching microflora with classical and molecular biological methods
  • Biochemistry, physiology and systematics of leaching microorganisms
  • Establishment of a reference bank of leaching microorganisms from various leaching sites
  • Optimization of leaching
  • Development of strategies for prevention of unwanted leaching

Biocorrosion of metallic, mineral and polymer materials

  • Identification and characterization of corrosion-relevant groups of microorganisms
  • Understanding the role of microorganisms in corrosion processes
  • Development of methods for detection of microbial participation in corrosion events
  • Development of methods to avoid, mitigate and sanitize biocorrosion