Make Some Microbe Friends


It’s the coolest story I’ve seen in the past few days: The New York Times reported how an Italian  museum cleaned its priceless Michelangelo sculptures with an army of bacteria.  As Jason Horowitz wrote, “restorers and scientists quietly unleashed microbes with good taste and an enormous appetite on the marbles, intentionally turning the chapel into a bacterial smorgasbord.”

And you just want to kill them all with your hand sanitizers and anti-bacterial soaps. 

The Medici Chapel in Florence had the good fortune to be blessed with an abundance of works by Michelangelo, but the bad fortune to have had centuries of various kinds of grime building up on them.  In particular, over time the corpse of one Medici “…seeped into Michelangelo’s marble, the chapel’s experts said, creating deep stains, button-shaped deformations…”

This is, I assume, why they tell you not to touch the art.

Scientists picked a bacteria — Serratia ficaria SH7, in case you’re taking notes – that ate the undesired grime without also eating the underlying marble.   It wasn’t hazardous to humans either and didn’t create spores that might go elsewhere.  “It’s better for our health,” one of the art restorers told NYT.  “For the environment, and the works of art.”

The technique was a success, allowing the sculptures to look like they did centuries ago. 

Using such bacteria to clean art has been around for at a decade, and not just for sculptures.  Perhaps more surprising is bacteria isn’t just cleaning art, it’s also creating it; the American Society for Microbiology hosts an annual Agar Art Contest

If you’re impressed by that, researchers are teaching bacteria to read, or at least to recognize letters.  That’s not all they might learn to do.  “For example, the framework and algorithm in our study can be used to facilitate the design of living therapeutics, such as targeted drug release systems based on engineered probiotic bacteria systems,” the researchers say.   

The thing is, we not only don’t know what microbes do, or could do, but we have only a vague understanding how they surround us.  That’s starting to change.  We’ve known for some time that each of us has a unique microbiome (including mycobiome!).  What we didn’t realize until recently was that each urban area has its own microbiome as well. 

A new study took samples from the subway systems in 60 cities around the world, and found thousands of previously unknown viruses and bacteria.  There was a “core urban microbiome” that almost all the cities shared, but each city had its unique microbiome. 

The authors conclude:

…these data suggest that urban microbiomes should be treated as ecologically distinct from both surrounding soil microbiomes and human commensal microbiomes. Though these microbiomes undoubtedly interact, they nonetheless represent distinct ecological niches with different genetic profiles.

“Every city has its own ‘molecular echo’ of the microbes that define it,” said senior author Christopher Mason, a professor at Weill Cornell Medicine (WCM). “If you gave me your shoe, I could tell you with about 90% accuracy the city in the world from which you came.”

There may be, Dr. Mason thinks, as much biodiversity on a subway railing as in rainforest (which, if you’ve ridden any U.S. subways, probably does not come as a surprise).  He marvels: “I think it’s a wonderful affirmation of how much left we have to discover about the world.”

“The amount of microbial diversity is just incomprehensibly vast,” Erica Hartmann, a microbiologist who was not involved in the study told The New York Times.  “There’s so much out there that we just don’t really understand, and there could be all kinds of nifty biotechnologies and all kinds of fun chemistries that we’re not aware of yet.”

The researchers were able to identify “antimicrobial resistance genes” that indicated resistance to antibiotics and other antimicrobial agents.  Lead author David Danko speculated:

Can we give some kind of heads-up about what to look for? Can we track the spread of bacteria or genes that will make bacteria resistant to antibiotics in the future? Can we use this as a way to inform public health departments in the use of antibiotics going forward?

The team is creating a “global metagenomic map” of the organisms, and plans to keep swabbing to collect more sample.  A companion paper looked at the “air microbiome” of the subways systems, finding a similar “geographic specificity.” 

They’re all around us.  They’re in us.  We live in a microbial world.  Some argue that our microbiome should be considered another organ, although it may be more accurate to view it as a colony that tries to tolerate us.  However you view microbes, they’re not going away; if they did, we would as well.

The pandemic has caused all of us to fear the coronavirus, and to take measures to kill it.  We all desperately sought Clorox wipes, stayed away from other people and their viruses, and tried things like UV sterilization.  Scientists worry all these efforts may have unintended consequences.  “We’re starting to realize that there’s collateral damage when we get rid of good microbes, and that has major consequences for our health,” said B. Brett Finlay, first author of a paper on the topic in PNAS.

As Dr. Finley told James Hamblin for The Atlantic. “The microbes we carry around are involved in many of the fundamental processes of Homo sapiens.”  Brendan Bohannan, a professor at the University of Oregon, agreed, telling The New York Times: “The more we learn about our relationships with the microbial world, the clearer it is that we are connected to them and to the rest of the natural world.” 

Mr. Hamblin concluded: “The ongoing challenge is to avoid binary thinking about microbes: They are not simply good or bad, any more than people are, and neither is Purell.”

Last year I argued that modern medicine was reaching the kind of limits that classical physics did at the beginning of the 21st century, when quantum effects were starting to become known.  It required an entirely new approach to physics – quantum physics – to deal with them, and that ended up revolutionizing physics and our understanding of the world. 

Medicine needs that kind of “quantum” revolution, particularly in regards to understanding, accepting, and benefiting more from our coexistence with the microbial world.  If we can co-opt microbes to clean art, who knows what we can “convince” them to do for our health? 

Kim is a former emarketing exec at a major Blues plan, editor of the late & lamented Tincture.io, and now regular THCB contributor.