Colonization and bioweathering of monazite by <i>Aspergillus niger</i> : solubilization and precipitation of rare earth elements

Geoactive fungi play a significant role in bioweathering of rock and mineral substrates. Monazite is phosphate containing the rare earth elements (REE) cerium, lanthanum neodymium. Little known about geomicrobial transformations REE-bearing minerals which are also relevant to REE biorecovery from terrestrial extra-terrestrial reserves. The geoactive soil fungus Aspergillus niger colonized monazite solid liquid growth media without any apparent inhibition. In glucose-minerals salts medium, enhanced mycelium extensively covered particle surfaces, probably due provision essential trace metals. Teeth-like pagoda-like etching patterns indicated dissolution, with extensive precipitation secondary oxalate minerals. Biomechanical forces ensued causing aggressive effects by tunnelling, penetration splitting ore particles. High amounts oxalic acid (~46 mM) moderate citric (~5 were produced 2% (wt./vol.) monazite, released. Correlation analysis suggested that was more effective than mobilization, although higher concentration implied complexant activity, as well prime REE-oxalate precipitation.