Formation of Sb₂O₃ microcrystals by Rhodotorula mucilaginosa

Area of Science:

• Environmental Microbiology
• Biomineralization
• Environmental Remediation

Background:

• Antimony (Sb) pollution poses significant risks to ecosystems and human health.
• Microbial induced mineralization, utilizing extracellular polymeric substances (EPS), converts toxic metal ions into stable mineral forms.

Purpose of the Study:

• To screen an efficient antimony-resistant microorganism for Sb(III) transformation.
• To investigate the role of microbial extracellular polymeric substances (EPS) in Sb(III) biomineralization.
• To explore strategies for remediating antimony-contaminated environments.

Main Methods:

• Screening of Sb-resistant Rhodotorula mucilaginosa.
• Analysis of Sb(III) transformation into Sb2O3 microcrystals mediated by EPS.
• Investigation of the influence of extracellular biomacromolecules and pH on Sb2O3 morphology and size.

Main Results:

• An efficient Sb-resistant R. mucilaginosa strain was identified, tolerating up to 41 mM Sb(III).
• R. mucilaginosa effectively removed 70% of 22 mM Sb(III) by transforming it into Sb2O3 microcrystals via EPS.
• Inducible and non-inducible extracellular biomacromolecules were found to control the morphology and size of Sb2O3 microcrystals.

Conclusions:

• Rhodotorula mucilaginosa can effectively remove Sb(III) by biomineralization into Sb2O3 microcrystals, controlled by EPS.
• This study elucidates Sb(III) biomineralization mechanisms involving R. mucilaginosa and EPS.
• The findings provide a basis for developing microbial remediation strategies for antimony-contaminated sites.