Metabolomic Analysis Reveals Contributions of Citric and Citramalic Acids to Rare Earth Bioleaching by a Paecilomyces Fungus

Bibliographic Details
Title: Metabolomic Analysis Reveals Contributions of Citric and Citramalic Acids to Rare Earth Bioleaching by a Paecilomyces Fungus
Authors: Vanessa L. Brisson, Wei-Qin Zhuang, Lisa Alvarez-Cohen
Source: Frontiers in Microbiology, Vol 10 (2020)
Publisher Information: Frontiers Media S.A., 2020.
Publication Year: 2020
Collection: LCC:Microbiology
Subject Terms: bioleaching, rare earth elements, thorium, metabolomics, Paecilomyces, phosphate solubilizing, Microbiology, QR1-502
More Details: Conventional methods for extracting rare earth elements from monazite ore require high energy inputs and produce environmentally damaging waste streams. Bioleaching offers a potentially more environmentally friendly alternative extraction process. In order to better understand bioleaching mechanisms, we conducted an exo-metabolomic analysis of a previously isolated rare earth bioleaching fungus from the genus Paecilomyces (GenBank accession numbers KM874779 and KM 874781) to identify contributions of compounds exuded by this fungus to bioleaching activity. Exuded compounds were compared under two growth conditions: growth with monazite ore as the only phosphate source, and growth with a soluble phosphate source (K2HPO4) added. Overall metabolite profiling, in combination with glucose consumption and biomass accumulation data, reflected a lag in growth when this organism was grown with only monazite. We analyzed the relationships between metabolite concentrations, rare earth solubilization, and growth conditions, and identified several metabolites potentially associated with bioleaching. Further investigation using laboratory prepared solutions of 17 of these metabolites indicated statistically significant leaching contributions from both citric and citramalic acids. These contributions (16.4 and 15.0 mg/L total rare earths solubilized) accounted for a portion, but not all, of the leaching achieved with direct bioleaching (42 ± 15 mg/L final rare earth concentration). Additionally, citramalic acid released significantly less of the radioactive element thorium than did citric acid (0.25 ± 0.01 mg/L compared to 1.18 ± 0.01 mg/L), suggesting that citramalic acid may have preferable leaching properties for a monazite bioleaching process.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1664-302X
Relation: https://www.frontiersin.org/article/10.3389/fmicb.2019.03008/full; https://doaj.org/toc/1664-302X
DOI: 10.3389/fmicb.2019.03008
Access URL: https://doaj.org/article/b90f9867b5524eabb3a971d9bb6c8209
Accession Number: edsdoj.b90f9867b5524eabb3a971d9bb6c8209
Database: Directory of Open Access Journals
More Details
ISSN:1664302X
DOI:10.3389/fmicb.2019.03008
Published in:Frontiers in Microbiology
Language:English