Microbial Data Mining
A friend of mine, a self-described “microbial supremacist” at Small Things Considered shows how animals make use of microbial odors.
How do hoverflies locate aphids–a garden pest we wish to control? The aphids secrete honeydew, which the aphid’s symbiotic bacteria ferment to various volatile compounds. These compounds attract the hoverflies to lay their eggs.
How do malaria mosquitoes locate the choice spot to bite a human? They follow an odor trail from the smelly feet, that is, the part where feet-specific microbes produce volatile compounds. Research funded by the Bill and Melinda Gates Foundation has identified ten specific microbial feet odor compounds that attract mosquitoes. The odor compounds, of course, are detected by specific receptor molecules on the neurons (similar to visual perception and cocaine receptors–sorry, couldn’t resist).
Bacteria, too, use their own “data” to adjust behavior. An elaborate system is quorum sensing, in which bacteria “count” their population by measuring the concentation of an “autoinducer” compound secreted continually by all members. Some bacteria even distinguish between counting their own, versus counting a different signal by other species. Pathogens such as Salmonella and M. tuberculosis may do this to adjust their pathology depending on what other pathogens are present.
What are other kinds of microbial data mining? How might this be used in science fiction?