Biopreservation of Art: Microbes as Art Protectant 

Different arts represent different eras of human civilization. Art plays a significant role in understanding the lives lived by our ancestors. From stone sculptures to monumental paintings, all art relics are susceptible to environmental deterioration and degradation by microbes that grow in the illustrations.

It is well known that microbes deteriorate artworks that threaten serious damage to these pieces. But preserving these paintings and sculptures means using harsh chemicals that cause even more damage to the artworks. 

However, one can avoid biodeterioration by using the biopreservation method of art. The biopreservation of art involves using some group of microbes that feed on the grime in paintings and softening the stones. This method can help in conserving the artworks. 

Concept of Biopreservation of Art

The use of different biological materials and techniques in preserving and protecting artworks is known as biopreservation of art. Here, biological methods and different biological principles are used to preserve the art relics. These methods are helpful in showing the deterioration of art objects caused by biological agents like microorganisms, insects, and fungi. 

The condition and longevity of artifacts highly depend on biological factors. The raw material for art production is usually organic materials like paper, canvas, paint, natural dyes, or wood. These organic materials are easy targets for biological deterioration after some time. Temperature, humidity, environmental pollutants, and light exposure also aid in the decomposition of the artwork. The biopreservation methods of art conservation includes:

1. Preventing and controlling the growth of biological degradant: As discussed earlier, the growth of harmful and degrading microbes and insects can destroy art and art materials. So, their growth must be controlled and prevented. Regularly cleaning the artwork, applying appropriate storing and displaying methods, and maintaining the right environmental conditions like temperature and humidity can aid in controlling the growth. However, this method of preventing growth applies to the internal environment. Continuous monitoring and rapid removal of problematic microbes should be done for external or outdoor environments.  
2. Using chemical and mechanical removal methods: Mechanical methods include using tools like brushes, scalpels, vacuum, and pressure to remove the contaminants from the arts. Chemical treatment includes using biocides, insecticides, and fungicides to preserve the artwork. Another method of removing contaminants is blasting the painting with lasers and gamma irradiation.   
3. Growing natural protectants: Although most microbes destroy art and artworks, some microbes can aid in conserving them. These protect the artwork by feeding on the unwanted layers from paintings or breaking down harmful substances on art objects. These are termed biocleaners.    
4. Continuous study and monitoring: There is a different biological process that causes the deterioration of the art. Constant studying and monitoring of these processes help in developing new preservation techniques. DNA analysis and microscopic observation help identify, track, and monitor the biological agents in artworks. The continuous analysis of DNA is another effective method for controlling and preventing the growth of harmful microbes in paintings and other artworks. 

Different Methods of Biopreservation of Art

There are different methods applicable for making microbes effective art protectants. Some of them are as follows:  

1. Bio cleaning: Using microbes to clean unwanted and degrading components from art and art relics. Microbes are applied directly in the art. The microbes metabolize the harmful deposits, including organic matter and salts. This metabolization helps in removing the stakes and helps restore the art relics. A recent article claims that Pseudomonas stutzeri strain A29 successfully cleaned nearly 400-year-old wall paintings at the Vatican Museums and Pisa Cathedral Cupola in Italy. This method is also useful is removing graffiti from different artworks.  
2. Bioconsolidation: Some bacteria produce calcium components that cushion the damaged stone sculptures. Bacteria like Bacillus and Desulfovbrio can create these calcium build-ups. Many studies are conducted on this preservation method, but one of the promising results was in isolated bacteria from stone blocks a the San Jeronimo Monastery in Spain. Here, they found the biomineralization capacity of different bacterial isolates and reapplied them to the stone. After two years of analysis, abundant calcium carbonate was present in the stone sculpture. This research showed that there is a chance of consolidation using native microbes. 
3. Growth limitation: Another way to preserve art was by analyzing the antagonistic relationship between microbes. This method uses different microbes to produce various components that can limit the growth of other microbes with a potentially high risk of deterioration. For example, Bacillus has different elements that can determine paint-dwelling harmful fungi and bacteria growth. The spores produced by Bacillus species limited the growth of fungi and bacteria isolated from a 17th-century painting. The bacteria also produce biocides and fungicides, and even after five months of study, there was no harmful effects on the mural and paintings.    

Limitations of Biopreservation   

Although biopreservation is inexpensive and effective, it has some limitations, including damage to art. 

1. Unintentional damage to art: As we discussed earlier, biopreservation uses biocides or biological agents. The agents react with different components of the art. The reaction alters the appearance of the artwork and damages the painting during these alterations. The use of appropriate treatment methods and regular testing can help avoid this limitation. 
2. Susceptible to environmental conditions: The microbes used for biopreservation can degrade under different environmental conditions like temperature and humidity. The storage and display settings are the main reasons the biopreservation method fails. So, properly storing and displaying the artworks play a significant role in the growth of microbes or the inefficacy of preservation treatments. 
3. Limited study on long-term effectivity and reversibility: This limitation states that the data on the long-term effects of biopreservation is lacking. This lack of data can lead to misunderstanding the potential risk and determining the correct method used for biopreservation. Some biocides can have irreversible effects on art forms, harming the artwork and not preserving it.    
4. Safety concerns: Bio-preservative methods can lead to health and safety issues in art handlers, conservators, and viewers. For example, spores of  Bacillus species can lead to a high risk of illness and disease in humans. Safe handling and application of biocides are necessary for providing safety to the concerned bodies. In addition, the hazardous materials, if not disposed of properly, can also lead to health risks for handlers.  

References and Further reading

• Ciferri O. (1999). Microbial degradation of paintings. Applied and environmental microbiology, 65(3), 879–885. https://doi.org/10.1128/AEM.65.3.879-885.1999 
• BARRON, M. (2021) Microbes as enemies and allies in the world of art conservation, ASM.org. Available at: https://asm.org/Articles/2021/December/Microbes-as-Enemies-and-Allies-in-the-World-of-Art 
• Ranalli, G. et al. (2019) ‘Onsite advanced biocleaning system for historical wall paintings using new agar-gauze bacteria gel’, Journal of Applied Microbiology, 126(6), pp. 1785–1796. doi:10.1111/jam.14275.