Tuesday, May 10, 2005

Seeking out new life...

Algae have been discovered that use cadmium as a nutrient.

Scientists have discovered cadmium within an enzyme from a marine diatom, an algae or plankton common in the ocean and a major source of food for many organisms. The finding, reported in the May 5 issue of Nature, suggests that certain trace metals, found in very low concentrations in the ocean, are utilized by enzymes that have not been found in organisms from terrestrial environments.

Life in the oceans may well use lots of weird metals because of evolutionary pressure.

"Trace elements are extremely scarce in the ocean," Saito said. "Major regions of the surface oceans, for instance, are known to be limited by iron, rather than by nitrogen or phosphorus as in lakes and coastal waters. This fact has created a selection for novel metalloenzymes and biochemistries that utilize metals that wouldn't otherwise be used in terrestrial or near-shore environments."

I suspect every naturally-occurring element will probably turn out to be an essential nutrient, at least for something.

No comments: