Using bacteria to clean art

Cleaning valuable works of art is an extremely tricky process.  The restorer must remove dirt and salts without damaging the original paint or substrate.  Researchers from the Polytechnic University of Valencia, in conjunction with the restorers of the Sistine Chapel, have been using bacteria to help them clean murals.

The technique was first developed by University of Molise microbiologist Giancarlo Ranalli.  Briefly, the scientists apply a thin layer of gel containing the bacteria Pseudomonas to the artwork.  After about two hours, the gel is removed from the surface and any remaining bacteria are killed by the resulting dry environment.  During those few hours, the bacteria eat the white salt crusts that obscure the paintings.

Thus far, the technique has been successfully tested on two of the ceiling vaults in the heavily damaged Church of Santos Juanes (which had sustained both a devastating fire in 1936 and an improper restoration in the 1960’s).  The researchers plan to experiment with other strains of bacteria to remove other types of dirt or decomposition products.

Pilar Bosch of the Institute of Heritage Restoration working on the paintings in the Church of Santos Juanes in Valencia.

Credit: Image courtesy of Asociación RUVID.