TY - JOUR
T1 - Colonization and bioweathering of monazite by Aspergillus niger
T2 - solubilization and precipitation of rare earth elements
AU - Kang, Xia
AU - Csetenyi, Laszlo
AU - Gadd, Geoffrey Michael
N1 - Funding Information:
Xia Kang gratefully acknowledges the receipt of a joint PhD scholarship from the School of Life Sciences, University of Dundee and China Scholarship Council (No. 201606910077). G.M.G. gratefully thanks the Natural Environment Research Council (NE/M010910/1 (TeaSe); NE/M011275/1 (COG)) for financial support of the Geomicrobiology Group. The authors also greatly acknowledge Mr. Martin Eales, CEO of Rainbow Rare Earths (London, UK) for kindly providing the monazite sample and Dr. Yongchang Fan (Materials and Photonics Systems Group, University of Dundee) for assistance with scanning electron microscopy and energy‐dispersive X‐ray spectroscopy. 3
Publisher Copyright:
© 2021 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/1/18
Y1 - 2021/1/18
N2 - Geoactive fungi play a significant role in bioweathering of rock and mineral substrates. Monazite is a phosphate mineral containing the rare earth elements (REE) cerium, lanthanum and neodymium. Little is known about geomicrobial transformations of REE-bearing minerals which are also relevant to REE biorecovery from terrestrial and extra-terrestrial reserves. The geoactive soil fungus Aspergillus niger colonized monazite in solid and liquid growth media without any apparent growth inhibition. In a glucose-minerals salts medium, monazite enhanced growth and mycelium extensively covered rock particle surfaces, probably due to the provision of phosphate and essential trace metals. Teeth-like and pagoda-like etching patterns indicated monazite dissolution, with extensive precipitation of secondary oxalate minerals. Biomechanical forces ensued causing aggressive bioweathering effects by tunnelling, penetration and splitting of the ore particles. High amounts of oxalic acid (~46 mM) and moderate amounts of citric acid (~5 mM) were produced in liquid media containing 2% (wt./vol.) monazite, and REE and phosphate were released. Correlation analysis suggested that citric acid was more effective than oxalic acid in REE mobilization, although the higher concentration of oxalic acid also implied complexant activity, as well as the prime role in REE-oxalate precipitation.
AB - Geoactive fungi play a significant role in bioweathering of rock and mineral substrates. Monazite is a phosphate mineral containing the rare earth elements (REE) cerium, lanthanum and neodymium. Little is known about geomicrobial transformations of REE-bearing minerals which are also relevant to REE biorecovery from terrestrial and extra-terrestrial reserves. The geoactive soil fungus Aspergillus niger colonized monazite in solid and liquid growth media without any apparent growth inhibition. In a glucose-minerals salts medium, monazite enhanced growth and mycelium extensively covered rock particle surfaces, probably due to the provision of phosphate and essential trace metals. Teeth-like and pagoda-like etching patterns indicated monazite dissolution, with extensive precipitation of secondary oxalate minerals. Biomechanical forces ensued causing aggressive bioweathering effects by tunnelling, penetration and splitting of the ore particles. High amounts of oxalic acid (~46 mM) and moderate amounts of citric acid (~5 mM) were produced in liquid media containing 2% (wt./vol.) monazite, and REE and phosphate were released. Correlation analysis suggested that citric acid was more effective than oxalic acid in REE mobilization, although the higher concentration of oxalic acid also implied complexant activity, as well as the prime role in REE-oxalate precipitation.
UR - http://www.scopus.com/inward/record.url?scp=85100079328&partnerID=8YFLogxK
U2 - 10.1111/1462-2920.15402
DO - 10.1111/1462-2920.15402
M3 - Article
C2 - 33459476
JO - Environmental Microbiology
JF - Environmental Microbiology
SN - 1462-2912
ER -