Missing siderophores may account for why microbiologists can culture only about 1% of the microorganisms that they collect from diverse environments, according to Kim Lewis of Northeastern University and his collaborators there and at nearby Harvard Medical School, both in Boston, Mass. Without siderophores to bind iron for them, these microorganisms fail to grow in the lab despite being bathed in nutrients. If this explanation holds up, it should enable microbiologists to overcome what some of them call the "great plate count anomaly" and to learn a great deal more about countless recalcitrant species that were set aside as "nongrowers." The work appeared in the March 26, 2010 Chemistry & Biology.
