Besides sunlight, heat, humidity and other factors, paintings face deterioration over time because of bacteria. A group of Italian researchers now says that old paintings can be better preserved by adding more bacteria to the mix. They discovered that some bacterial spores will fight the bad microbes that eat away at oil paintings. 

According to a new paper published in PLOS One, the researchers found that several strains of bacteria–mainly Staphylococcus and Bacillus–break down elements of paintings. But adding the spores of another strain of the Bacillus bacteria–Bacillus subtilis, Bacillus pumilus, and Bacillus megaterium–helped kill the malignant microbes and fungi.

The test was successfully applied to a 17th-century painting attributed to Baroque master Carlo Bononi–the “Incoronazione della Vergine” (The Coronation of the Virgin), a huge oil on canvas that was removed from a wall after a 2012 earthquake damaged the Basilica of Santa Maria in Vado, in Ferrara, Italy.