Title : Green synthesis of magnetosomes by Acidithiobacillus ferrooxidans and their potential applications
Abstract:
Magnetosome, synthesized by magnetosome-producing bacteria including magnetotactic bacteria (MTB) and non-magnetotactic bacteria (Non-MTB), is a natural magnetic nanomaterial that integrates superparamagnetism, high stability, excellent biocompatibility, well-dispersibility and easily modifiable surface. It can be widely applied in biomedicine and bio-agriculture field. A. ferrooxidans, a typical non-MTB, only requires sufficient Fe(II) and suitable oxygen to produce magnetosome compared with MTB. Thus, it conferring greater flexibility and potential application in biomagnetic nanoparticles production. However, current mechanistic insights into magnetosome synthesis are mainly derived from studies on MTB. Therefore, we have systematically investigated the magnetosome synthesis characteristics of A. ferrooxidans. In our study, a magnetosome-producing bacterium A. ferrooxidans BYM was isolated and magnetically screened. The magnetosome produced by BYM consist of inorganic (Fe3O4) and organic components (lipid bilayer membrane). The magnetosome yield ranging from 0.5896 to 13.1291 mg/g was achieved under different aeration rates, as well as varying concentrations of ferrous sulfate, ammonium sulfate, and gluconic acid at 30 ℃. In order to further increase magnetosome production. We investigated the iron source selection, uptake mechanisms, and kinetic characteristics during magnetosome mineralization, and elucidated the underlying physicochemical processes. Furthermore, based on magnetosome phenomic parameters and multi-omics analyses, we propose a hypothetical model for magnetosome synthesis that includes membrane formation, iron uptake and transport, iron redox and crystal maturity. Our results will enable in-depth studies of magnetosome synthesis mechanism and yield improvement in non-magnetotactic magnetic bacteria. We have also further confirmed that magnetosomes hold significant application potential in the fields of drug delivery and biocatalysis.
