Organic molecules are involved in biomineralization by Streptomyces mirabilis

ABSTRACT: The Gram-positive, filamentous soil bacterium S. mirabilis P16B-1 has been shown to tolerate environmental concentrations of over 100 mM of Ni. The extremely high metal tolerance is partly provided through biomineralization observed for both Mg bearing struvite and Ni-struvite where Ni ions replace Mg in the mineral lattice. The capacity to induce mineral formation even at some distance to the cell surface indicated involvement of secreted substances in the process. Here, we could show that metabolites as well as proteins in the cell free culture natant promote mineralization. At the same time, the precipitation process if induced physically leads to some co-precipitation which might hint at first insight into nucleation. Proteomics and metabolomics were performed in sterile culture supernatant before or after precipitation of crystals was induced by freezing and thawing to obtain candidates for co-precipitated organic molecules. Three compounds could be identified to be co-precipitated with minerals formed. However, none had an impact on macro-morphology of crystals if added as pure substance. Hence, the proteome secreted by the cells was screened, and evidence for involvement of a nickel binding protein, NikA, could be obtained.

INSTRUMENT(S):

ORGANISM(S): Streptomyces Mirabilis

SUBMITTER: Thomas Krüger  

LAB HEAD: Axel A. Brakhage

PROVIDER: PXD049698 | Pride | 2026-07-07

REPOSITORIES: Pride