Rare Earth Elements: Review of Medical and Biological Properties and Their Abundance in the Rock Materials and Mineralized Spring Waters in the Context of Animal and Human Geophagia Reasons Evaluation

How Can Methanol Dehydrogenase from Methylacidiphilum fumariolicum Work with the Alien CeIII Ion in the Active Center? A Theoretical Study

“…Recently, in the waters of acidic hot spring of a volcano in south Italy, has been discovered the Methylacidiphilum fumariolicum bacterium (XoxF‐type) that operates at extreme living conditions and the structure of its MDH revealed the presence of rare earth elements (La, Ce, Pr, and Nd) rather than calcium . Lanthanides are not essential for human life, though they are ubiquitous at relatively low concentrations …”

Diversity, Abundance, and Some Characteristics of Bacteria Isolated from Earth Material Consumed by Wild Animals at Kudurs in the Sikhote-Alin Mountains, Russia

“…The most common of them are the need for sodium and mineral sorbents to normalize the electrolyte balance in the digestive tract of animals during the spring transition of animals to green food [ 2 – 4 ]; the need to replenish the body's lack of Fe; replenishment of symbiont microorganisms, parasite control, and regulation of pH in the digestive tract [ 5 – 7 ]; and removal of chemical wastes from the body using mineral sorbents [ 8 , 9 ]. More recently, based on the analysis of extensive data on the geochemistry of geophagic earths in various regions of the world, we proposed the rare-earth or “REE hypothesis” [ 10 ]. Its main point is that some elements from the light lanthanides group associated in nerve tissues and internal secretion gland enzymes can be replaced easily by heavy analogues, which, unlike the light ones, are unable to perform the functions necessary for the body.…”

Effect of Multivalent Cations on Intermolecular Association of Isotactic and Atactic Poly(Methacrylic Acid) Chains in Aqueous Solutions

“…Trivalent cations, such as La 3+ , also have an important role in biological processes [18]. They can act as calcium analogs in living systems and may thus substitute Ca 2+ in many proteins [19,20] and even in cell membranes [21] due to having a similar ionic radius (which is 1.0 Å for Ca 2+ and 1.18 Å for La 3+ [22]).…”

“…However, trivalent cations are not transported across the cell membrane. Lanthanides can thus be used as probes for Ca 2+ in biological systems [18,19,20,21] and as probes for interactions of metal ions with polyelectrolytes in solution in general when the role of counterion charge is investigated [23].…”