"Long before it's in the papers"
January 27, 2015


Even microbes carry out tiny “commerce,” study finds

Jan. 15, 2014
Courtesy of Northern Arizona University
and World Science staff

A clos­er look at mi­crobes re­veals there’s big busi­ness go­ing on in their very small world, and some­times we are part of the trans­ac­tion, sci­ent­ists say.

A team of re­search­ers in­clud­ing North­ern Ar­i­zo­na Uni­vers­ity sci­ent­ist Nan­cy Col­lins John­son ar­gue in the jour­nal Pro­ceed­ings of the Na­t­ional Acad­e­my of Sci­ences that mi­crobes, like many an­i­mals, are sav­vy traders, sell­ing high and buy­ing low.

A mi­cro­graph of plant roots col­o­nized with ar­bus­cu­lar my­c­or­rhizal fun­gi (stained blue). My­c­or­rhizas are well-known ex­am­ples of bi­o­log­i­cal "mar­kets"—the plant trades sug­ars for soil min­er­als. 

“Although hid­den from the na­ked eye, mi­croor­gan­isms are ac­tive in com­plex net­works of trade, swap­ping nu­tri­ents, hoard­ing re­sources and bar­ter­ing deals us­ing many of the same strate­gies hu­mans use to dom­i­nate mar­kets,” John­son said. 

“While we know such ‘bi­o­log­i­cal mar­kets’ ex­ist in na­ture be­tween cog­ni­tive [high­er] or­gan­isms—for ex­am­ple, when pri­ma­tes groom each oth­er in ex­change for food—it is dif­fi­cult to im­ag­ine mar­kets emerg­ing” on such a small scale.

Yet all or­gan­isms, in­clud­ing hu­mans, co­op­er­ate with ben­e­fi­cial mi­crobes, she not­ed. “For ex­am­ple, our gut bac­te­ria give us vi­ta­mins and nu­tri­ents and are cru­cial to our well-being,” John­son said.

Mi­crobes al­so co­op­er­ate with plants. John­son and the oth­er au­thors dis­cuss di­verse eco­nom­ic strate­gies em­ployed by mi­crobes, in­clud­ing avoid­ing bad trad­ing part­ners, sav­ing for a rainy day and build­ing lo­cal busi­ness ties.

The pa­per, “Evo­lu­tion of Mi­cro­bi­al Mar­kets,” arose from a work­ing group of sci­ent­ists at the Lo­rentz Cen­ter in Lei­den, The Neth­er­lands, in Jan­u­ary 2012.

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A closer look at microbes reveals there is big business going on in their very small world, and sometimes we are part of the transaction. A team of researchers including Northern Arizona University scientist Nancy Collins Johnson argue in the journal Proceedings of the National Academy of Sciences that microbes, like many animals, are savvy traders, selling high and buying low. “Although hidden from the naked eye, microorganisms are active in complex networks of trade, swapping nutrients, hoarding resources and bartering deals using many of the same strategies humans use to dominate markets,” Johnson said. “While we know such ‘biological markets’ exist in nature between cognitive organisms—for example, when primates groom each other in exchange for food—it is difficult to imagine markets emerging” on such a small scale. Yet all organisms, including humans, cooperate with beneficial microbes, she noted. “For example, our gut bacteria give us vitamins and nutrients and are crucial to our well-being,” Johnson said. Microbes also cooperate with plants. Johnson and the other authors discuss diverse economic strategies employed by microbes, including avoiding bad trading partners, saving for a rainy day and building local business ties. The paper, “Evolution of Microbial Markets,” arose from a working group of scientists at the Lorentz Center in Leiden, The Netherlands, in January 2012.