Editor's Summary
5 January 2006
P soup for nitrogen fixers
Nitrogen-fixing Trichodesmium are the primary source of 'new' nitrogen to tropical and subtropical oceans, yet little is known about the cellular adaptations that allow these bacteria to thrive. Trichodesmium's success in low dissolved inorganic phosphate regimes, like the Western North Atlantic, suggests that it is an efficient phosphorus scavenger, able to make use of dissolved organic phosphorus. This hypothesis is confirmed in a new study in the Sargasso Sea. Trichodesmium appears to acquire phosphorus from phosphonate compounds using a C–P lyase. This type of bond has long been considered refractory: but the genes for phosphonate metabolism are present in the T. erythraeum genome and all the Trichodesmium species so far tested.
News and Views: Oceanography: A phosphate alternative
A major player among the phytoplankton can exploit a source of phosphorus previously thought to be unavailable to it. That ability may provide an ecological advantage in nutrient-depleted regions of the open ocean.
Sergio A. Sañudo-Wilhelmy
doi:10.1038/439025a