Microbial Ecology and Evolution

Paradoxes in Microbial Interactions


Three new principles of microbial community interaction have been discovered by researchers at the Santa Fe Institute in New Mexico led by Eric Libby.

The first new principle is The Curse of Increased Efficiency.  When Organism A is much better at making a certain metabolite than Organism B, Organism B turns into a moocher, stops trying to produce the metabolite, and grabs it from Organism A’s surplus.  This means that Organism B reproduces faster with less effort and eventually takes over the colony.

The second principle is The Curse of Decreased Inefficiency.  When all the organisms in a colony get better at making a metabolite, the colony grows more slowly.

“This occurs because it leads to a lack of specialization,” said Libby.  “The community as a whole becomes less efficient and grows more slowly.”  When everyone becomes a jack-of-all-trades, apparently nothing gets done very well.

Although the first two principles assume that all cell types in a community make their own metabolic decisions, the third principle – The Curse of Control – assumes that one microbe can manipulate the others into following a particular strategy.  The manipulator bacterium may initially increase in number, but becomes a smaller part of the community in the long term.  “Depending on the length of time of an association, it may be more beneficial to compete with another microbe than to exploit it,” the authors explained.

For more information, go to the November 8 issue of Nature Communications.