( Microbes may compete with large animal ...)Microbes compete with animals for food by making it stink

Ecologists have long recognized microbes as decomposers and pathogens in ecological communities. But their role as classic consumers who produce chemicals to compete with larger animals could be an important and common interaction within many ecosystems -- and one that scientists often overlook, according to the authors of a paper published this week in the journal Ecology.

"There is the notion that these spoiled resources are not that important," said Mark Hay, a Georgia Institute of Technology professor of biology, who led a team of graduate students conducting the research. "But when you total them up, they are appreciable, especially in marine ecosystems.

"Microbes that can hold onto these resources and use them for their own growth would be advantaged over microbes that could not prevent their resource from being consumed by animals," Hay added. "If microbes could produce chemicals that prevented crabs or fishes from using these resources, then those microbes should gain an advantage and become more abundant." __IMAGE_2

As part of an interdisciplinary graduate training program funded by the National Science Foundation, Hay, two of his faculty colleagues and four Ph.D. students tested this notion with a field and lab study they began at the Skidaway Institute of Oceanography near Savannah, Ga., in summer 2002. They were prompted by an assertion made in a paper published in 1977 by ecologist Dan Janzen, who suggested that microbes are rotting fruits, molding seeds and spoiling meat to make these resources repugnant to other animals, allowing microbes to consume them instead.

To test whether aged meat attracts fewer consumers than fresher meat, researchers baited crab traps with menhaden -- a fish typically
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Source:Georgia Institute of Technology Research News