Microbes at the Museum
Name of Artwork: Excavation (1926)
Location: Harn Museum, Gainesville Fl.
Art Medium: Tempera on plaster (egg yolk tempera)
Species Identity: A fungus is most likely causing the biodeterioration in this painting, in particular the culprit may be Aureobasidium pullulans which is known to cause cracking in paint, like what is seen in the piece.
Describing Biodegradation: In this piece of artwork lots of cracking can be seen which is a sign of biodegradation. The cracking could be caused by the growth of the fungus between paint layers and the subrtate that causes pressure resulting in cracking. The fungus A. pullunans grows in a wide range of temperatures, but its optimal temperature is 25 °C. The egg yolk binder provides sufficient nutrients for the fungus to grow.
Danger and Preservation: The danger to the artwork is very physical, the paint can continue to crack more and more until it is no longer attached which can result in a very devastating ending for this piece. The harn museum is able to fumigate pieces of artwork, which could help. A layer of clear paint could be applied over the piece as well to protect it from any further colonization and cracking.
Name of Artwork: Lathyrus Odoratus (1840)
Location: Harn Museum, Gainesville Fl.
Art Medium: Lithograph, hand colored
Species Identity: The brown stain could be due to Penicillium brevi-compactum, or Cladosporium cladosporioides which have been found to produce greenish-brown black stains in past mural paintings.
Describing Biodegradation:The piece of artwork has a brownish-black stain that is circular, the stain easily stands out from the creme color if the paper. C. cladosporioides is a fungus that is exremely common and found on decaying organic materials as well as paper, pulp and paint. This fungus is xerophilic and its optimal growing temperature is 18-28 ° C, these conditions are common characteristics of places that may harbor this type of artwork.
Danger and Preservation: If this biodeterioration was to be left untreated the spot could grow much larger than it currently is. The Harn Museum is able to fumigate pieces of artwork to ensure that no species continue living on the artwork. They also pay close attention to the artwork and don't display it until it has been properly treated. By putting this piece in a glass frame, there is less to worry about with the environmental conditions, which is a key step in preventing damage.
Name of Artwork: Au Theatre (The Theater) (1935)
Location: Harn Museum, Gainesville Fl.
Art Medium: Oil on canvas
Species Identity: Several bacteria are known to cause damage, as seen in this piece of artwork, as well as in other oil based paintings, including: Alcaligenes, Bacillus, Flavobacterium, and Micrococcus.
Describing Biodegradation: Severe cracking or peeling can be seen in this piece of artwork, which is a sign of biodegradation. The bacteria is able to brreak down the resinous binders in the paint causing a loss of adhesion to the substrate. Although this piece of artwork isn't too broken down between the paint and the substrate, one can see where the paint is splitting and detatching. The bacteria are able to utilize the nitrate in the oil paints as nutrients for colonization and growth.
Danger and Preservation: If this deterioration is left untreated the cracking and peeling may cause even more seperataion and could ultimately result in the whole piece falling apart. To get rid the possible bacterial species the museum can fumigate it as well as store it environments that are cool and dry so that growth doesn't occur. Lighting is also important to control in oil paintings, diffused natural or artificial light is optimal, whereas, direct sunlight can cause the paint to become more brittle and crack.