The idea of everyone in a community pitching in is so universal that even bacteria have a system to prevent the layabouts of their kind from enjoying the fruit of others’ hard work, Princeton University researchers have discovered.
Groups of the bacteria Vibrio cholerae deny loafers their unjust desserts by keeping the food generated by the community’s productive members away from V. cholerae that attempt to live on others’ leftover nutrients, the researchers report in the journal Current Biology. The researchers found that individual bacteria produce a thick coating around themselves to prevent nutrients from drifting over to the undeserving. Alternatively, the natural flow of fluids over the surface of bacterial communities can wash away excess food before the freeloaders can indulge.
Likely common among bacteria, this act of microscopic justice not only ensures the survival of the group’s most industrious members, but also could be used for agriculture, fuel production and the treatment of bacterial infections such as cholera, explained first author Knut Drescher, a postdoctoral research fellow in the lab of senior author Bonnie Bassler, the Squibb Professor inMolecular Biology and department chair.
By encouraging this action, scientists could increase the efficiency of any process that relies on bacteria to break down organic materials, such as plant materials into biofuels, or cellulose into paper products, Drescher said. For treating a disease, the mechanism could be counteracted to effectively starve the more productive bacteria and weaken the infection.
“We could use our discovery to develop strategies that encourage the proliferation of microbes that digest dead organic material into useful products,” Drescher said. “Such an approach will be useful for optimizing nutrient recycling for agriculture, bioremediation, industrial cleanup, or making products for industry or medicine.”
The Princeton findings also provide insight into how all microbes potentially preserve themselves by imposing fairness and resolving the “public goods dilemma,” in which a group must work together while also avoiding exploitation by their self-serving individuals, said co-lead author Carey Nadell, a postdoctoral research associate in Bassler’s lab.
“The public goods dilemma is a central problem in the history of life on Earth, during which single cells have emerged as collectives of genes, multicellular organisms have emerged as collectives of cells, and societies have emerged as collectives of multicellular organisms,” Nadell said.
“At each of these transitions in complexity there has been — and remains — the threat of exploitation by single members pursuing their own interests at the expense of the collective as a whole,” Nadell said. “Clarifying how exploitation can be averted is therefore critical to understanding how life has taken the various forms that exist today.”