Fungal biorecovery of cerium as oxalate and carbonate biominerals

Author(s)

Kang, Xia ; Csetenyi, Laszlo ; Gadd, Geoffrey Michael

• Document type: Journal article
• Source: FUNGAL BIOLOGY; v. 127, n. 7-8, p. 11-pg., 2023-07-01.

Abstract

Cerium is the most sought-after rare earth element (REE) for application in high-tech electronic devices and versatile nanomaterials. In this research, biomass-free spent culture media of Aspergillus niger and Neurospora crassa containing precipitant ligands (oxalate, carbonate) were investigated for their po-tential application in biorecovery of Ce from solution. Precipitation occurred after Ce3+ was mixed with biomass-free spent culture media and >99% Ce was recovered from media of both organisms. SEM showed that biogenic crystals with distinctive morphologies were formed in the biomass-free spent medium of A. niger. Irregularly-shaped nanoparticles with varying sizes ranging from 0.5 to 2 mm and amorphous biominerals were formed after mixing the carbonate-laden N. crassa supernatant, resulting from ureolysis of supplied urea, with Ce3+. Both biominerals contained Ce as the sole metal, and X-ray diffraction (XRD) and thermogravimetric analyses identified the biominerals resulting from the biomass-free A. niger and N. crassa spent media as cerium oxalate decahydrate [Ce2(C2O4)3.10H2O] and cerium carbonate [Ce2(CO3)3.8H2O], respectively. Thermal decomposition experiments showed that the biogenic Ce oxalates and carbonates could be subsequently transformed into ceria (CeO2). FTIR confirmed that both amorphous and nanoscale Ce carbonates contained carbonate (CO32 ⠂) groups. FTIR-multivariate analysis could classify the biominerals into three groups according to different Ce concentrations and showed that Ce carbonate biominerals of higher purity were produced when precipitated at higher Ce3+ concentrations. This work provides new understanding of fungal biotransformations of soluble REE species and their biorecovery using biomass-free fungal culture systems and indicates the potential of using recovered REE as precursors for the biosynthesis of novel nanomaterials. & COPY; 2022 The Author(s). Published by Elsevier Ltd on behalf of British Mycological Society. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). (AU)

• FAPESP's process: 21/13614-3 - IV International Symposium on Fungal Stress - ISFUS & XIII International Fungal Biology Conference - IFBC
• Grantee: Drauzio Eduardo Naretto Rangel
• Support Opportunities: Organization Grants - Scientific Meeting