Accumulation of rare earth elements by siderophoreforming Arthrobacter luteolus isolated from rare earth environment of Chavara, India.

In this study, Arthrobacter luteolus, isolated from rare earth environment of Chavara (Quilon district, Kerala, India), were found to produce catechol-type siderophores. The bacterial strain accumulated rare earth elements such as samarium and scandium. The siderophores may play a role in the accumulation of rare earth elements. Catecholate siderophore and low-molecular-weight organic acids were found to be present in experiments with Arthrobacter luteolus. The influence of siderophore on the accumulation of rare earth elements by bacteria has been extensively discussed.

Studies on the distribution of bacterial isolates in rare earth environment.

Rare earth soil is precious, but very common across Arabian coast especially in Chavara, (Quilon district, Kerala) south west coast of India. They are widely distributed but usually occur in small amounts and enhance the soil properties. In the present study, 18 different bacterial isolates were identified from three different samples such as soil and biofilm formed on metal surfaces from the rare earth environment of Chavara using 16S rDNA gene sequencing. The accumulation of rare earth elements (REE) by microbes was studied using FT-IR analysis. In the FTIR spectrum of the test system, a peak at 1548 and 1449 cm-1 indicates the presence of aromatic nuclei (carboxylic acid), while C=C stretch for C-O-C group was noticed at 1237 cm-1. Thus significant variations in the peak position confirm the presence of carboxyl group and thus it was confirmed that rare earth elements induce the bacteria to produce carboxylic acid and thereby accumulate rare earth elements.