Tellurium, unlike the elements above it in the periodic table,
is not thought to be required by biological systems. However, tellurium-resistant fungi grown in
the absence of sulfur and in the presence of tellurite ions incorporated tellurium into amino acids and
proteins (Ramadan et al, 1989). Tellurium is considered to be toxic to most organisms. Genes correlated with tellurium
resistance have been identified, but the mechanisms of tellurium resistance are not completely understood (reviewed by Taylor, 1999).
Reduction of tellurite to insoluble elemental tellurium has been described in
Gram-positive and Gram-negative bacteria and archaea, and is one mechanism of microbial tellurium resistance (reviewed by Chasteen and Bentley, 2003). Nitrate reductases (Sabaty et al, 2001) and terminal oxidases in the respiratory electron transport chain (Trutko et al, 2000) have been implicated in tellurium reduction. Biomethylation of tellurite, tellurate, and elemental tellurium to volatile
dimethyltellurium has been observed in several species of bacteria and fungi, and may represent another mechanism of tellurium
resistance (reviewed by Chasteen and Bentley, 2003).
For more information:
Medline for tellurium metabolism AND bacteria