Tellurium, biological role

Unlike selenium there is no required biological role for tellurium in bacteria or plants that has been determined however, this may ultimately not be the whole story.111 Selenium was only viewed as a toxic metalloid with no necessary role for metabolism until at least the 1950s see above. While tellurite is less soluble than tellurate in aqueous solution, in general tellurite is probably more toxic to most organisms.190 The non Te-resistant wild type E. coli bacterium (Gramnegative) has MICs of 1 to 3 ppm for tellurite and tellurate.144,191,192 Tellurite is used to enrich and select for Staphylococcus aureus.169,193,194... 

Tellurium has no significant biological role. Tellurium and tellurium compounds should be considered to be toxic and need to be handled with care. Organic tellurides have been employed as initiators for living radical polymerization, and electron-rich mono- and di-tellurides possess antioxidant activity. Humans exposed to as little as 0.01 mg/m or less in air develop "tellurium breath", which has a garlic-like odor. This is due to formation of ethyl telluride within the body. 

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