❝ You share more than a zip code with your neighbors. You also share bugs — microscopic organisms (think bacteria, fungi, and viruses). These microbial communities are called microbiomes, and they seem to have an impact on everything from digestion to allergies. They also happen to be everywhere — from your intestines to your phone’s screen to the sidewalk beneath your feet.
But those bugs are tough to understand, because you can’t see them. “There’s like this whole other invisible planet,” says Kevin Slavin, head of the Playful Systems group at the MIT Media Lab. In a new project called Holobiont Urbanism, Slavin’s team is working to sample, sequence, and visualize the microbial makeup of New York City. Some of the team members are designers, engineers, and biologists.
❝ Bees typically forage no more than a mile and a half from their hives, but in their expeditions they come into contact with the microbes in their range, and those microbes stick. Slavin’s group worked with apiarists to build beehives with removable trays at the bottom that collect detritus from the bees, like a crumb-catcher in a toaster. Then they put those hives all over Brooklyn and Queens (and Sydney, Melbourne, Venice, and Tokyo).
Researchers can gather up all those bee-crumbs and sequence the DNA they find. Subtract the bee genes and what’s left represents the neighborhood microbiome. Slavin’s team mapped all those genes into a a circular evolutionary tree…but for specific urban areas. They also mapped microbes to their homes. New York City and Sydney, for example, both harbor the genera Polaromonas, Sphingopyxis, and Alicycliphilus, all of which feed on pollutants. But Venice has Meyerozyma guilliermondii and Penicillium chrysogenum, two dampness-loving fungi associated with wood rot.
❝ What does that teach you about cities? Maybe not much. Cataloging bug DNA might not say much about the urban microbiome as a whole…just being able to see this invisible microbial world is at least a step toward understanding it…A city is about more than architecture and infrastructure and people; it’s about the bugs everyone shares, too.
Some of those little critters are harmful to us. Some aren’t. Many of them probably affect our lives in a number of ways which can’t be categorized in simple fashion. But, increasing knowledge also increases the likelihood of expanding understanding.