In the darkest months of the global pandemic, a team of scientists and art restorers in Florence unleashed a bacteriological bioweapon on Michelangelo masterpieces in the Medici Chapels to clean them from centuries of stubborn grime.
A trio of oil, glue and phosphate-consuming microbes employed by the all-woman team of Italian experts has successfully eaten away at stains and residues besmirching the world-famous marble sculptures inside the mausoleum Michelangelo designed for the Medici at the Basilica of San Lorenzo.
Medici Chapel officials are expected to release today new details about the experiment’s efficacy, showcasing how innovative biological technology can help restore sculptures, paintings and other delicate works marred by the passage of time.
The little-known bacterium used to clean up the world famous works were sourced from rather humbler surroundings. One was Serratia Ficaria, known as SH7, which had been isolated in an abandoned Sardinian lead and zinc mine, another was Pseudomonas stutzeri CONC11, which came from a tannery near Naples, and the third was Rhodococcus sp. ZCONT, discovered in diesel-contaminated soil near Caserta.
After just two overnight sessions, the microbes had removed grime present for the last 500 years in the New Sacristy, which houses the largest concentration of Michelangelo’s works in one location, including four allegorical sculptures symbolizing day, night, dawn and dusk.
“In theory we believed it would work because we were using microorganisms that we know have certain applications,” said Annarosa Sprocati, who led a team of microbiology researchers from the Italian National Agency for New Technology. “But it was beautiful when we took the xanthan gel packs off the statues and could see the packs were no longer white but had turned a horrible colour . . . we knew it had been successful.”
The miracle microbes worked overnight. But it had taken the team of scientists, museum officials and restorers eight years of joint analysis, diagnosis and testing to determine how best to solve the problem inside the funeral monument.