The accumulation of rare-earth yttrium ions by Penicillium sp. ZD28.

To obtained fungal resources with excellent tolerance and accumulation capacity to rare earth yttrium ions (Y), rare earth ore samples were collected and used for microbial screening. A fungus hyper-resistant to Y was obtained and the effects of the fungus in three physiological states (growth process, mycelial pellets with physiological activity and the fungus powder after being ground) on the Y accumulation were investigated. The Y resistant fungus was identified as Penicillium sp. ZD28, and its mycelium pellets (about 1 mm in diameter) showed poor ability to accumulate Y with an adsorption capacity of less than 81 μmol/g. However, the fungus was able to remove 99% of Y during the growth process, at an initial concentration of less than 600 μM. Bioaccumulation of Y was observed on the cell surface of the ZD28 strain by elemental mapping using scanning electron microscopy-energy dispersive X-ray spectroscopy. The adsorbent (the dry fungal powder) had a remarkable adsorption property for Y that was greater than 455 μmol/g in conditions of 465 μM < [Y] < 6382 μM. Penicillium sp. ZD28 has major potential applications in the accumulation of yttrium group rare earth ions. This research has formed a theoretical foundation for the application of this biological method to extract rare earth ions in the mining and smelting of yttrium group rare earth elements.