Taking nature into lab: biomineralization by heavy metal-resistant streptomycetes in soil
- 1Microbial Communication, Institute of Microbiology, Faculty of Biology and Pharmacy, Friedrich-Schiller-University Jena, Neugasse 25, 07745 Jena, Germany
- 2Centre for Electron Microscopy, Clinical Centre, Friedrich-Schiller-University Jena, Ziegelmühlenweg 1, 07743 Jena, Germany
- 3Applied Geology Institute of Geosciences, Faculty of Chemistry and Earth Sciences, Friedrich-Schiller-University Jena, Burgweg 11, 07749 Jena, Germany
- 4Max Planck Institute for Biogeochemistry Jena- Biogeochemical Processes, Hans-Knöll-Strasse 10, 07745 Jena, Germany
- 5Mineralogy, Institute of Geosciences, Faculty of Chemistry and Earth Sciences, Friedrich-Schiller-University Jena, Burgweg 11, 07749 Jena, Germany
Abstract. Biomineralization by heavy metal-resistant streptomycetes was tested to evaluate the potential influence on metal mobilities in soil. Thus, we designed an experiment adopting conditions from classical laboratory methods to natural conditions prevailing in metal-rich soils with media spiked with heavy metals, soil agar, and nutrient-enriched or unamended soil incubated with the bacteria. As a result, all strains were able to form struvite minerals (MgNH4PO4• 6H2O) on tryptic soy broth (TSB)-media supplemented with AlCl3, MnCl2 and CuSO4, as well as on soil agar. Some strains additionally formed struvite on nutrient-enriched contaminated and control soil, as well as on metal contaminated soil without addition of media components. In contrast, switzerite (Mn3(PO4)2• 7H2O) was exclusively formed on minimal media spiked with MnCl2 by four heavy metal-resistant strains, and on nutrient-enriched control soil by one strain. Hydrated nickel hydrogen phosphate was only crystallized on complex media supplemented with NiSO4 by most strains. Thus, mineralization is a dominant property of streptomycetes, with different processes likely to occur under laboratory conditions and sub-natural to natural conditions. This new understanding might have implications for our understanding of biological metal resistance mechanisms. We assume that biogeochemical cycles, nutrient storage and metal resistance might be affected by formation and re-solubilization of minerals like struvite in soil at microscale.