Biosorption of lanthanum and samarium by viable and autoclaved mycelium of Botryosphaeria rhodina MAMB-05.

The ascomycetous fungus, Botryosphaeria rhodina MAMB-05, secretes a (1→3)(1→6)-β-D-glucan, and the scaled-up production of this β-glucan results in large amounts of mycelial biomass being produced that represent a potentially cost-effective biosorbent for rare-earth elements. High sorption capacities for both La(III) and Sm(III) were demonstrated for viable and autoclaved lyophilized fungal mycelium. Fourier-transformed infra-red absorption spectra and the point of zero charge (PZC) were similar for the viable and inactive fungal mycelia. The rare-earth lanthanide elements (La and Sm) binding increased at initial pH values greater than 5.0, which was also observed for the PZC determination. The maximum La(III) uptake capacity was observed at lower amounts of La(III) ions in solution, decreasing from 100.0 to 25.3% when the initial lanthanide concentration increased from 15 to 100 mg/L. Lanthanide biosorption by B. rhodina MAMB-05 mycelia followed the Langmuir model, and the affinity of biosorbent functional groups was similar for La(III) and Sm(III).