By: Chinwe Ifitezue (Institute of Archeology and Museums Studies, Jos)
For easy of assimilation, Biotechnology is a science of using organism to develop health care products and processes of their life span; or using biology to develop new products, methods and organisms intended to improve human health, society and valuables. Based on this definition, biotechnology has potentials which could be extended to other fields like cultural heritage as will be exposed in this piece rather than using it for medical purpose only.
Biotechnology, which simply put is the application of biology to produce new products, methods and organisms intended to improve human health and increase the value of products to the society has played key role in medicine, agriculture and industry for over 30 years and has advanced man’s understanding of the biological sciences. Furthermore, biotechnology has great and largely untapped potential for preservation and restoration of cultural heritage. It is possible that the tools of biotechnology are not often applied in the preservation and restoration of cultural heritage because of the inherent separation of the world of art and science; however, it is encouraging to see that during the past ten years important biotechnological applications to artwork preservation have emerged and advances in biotechnology predict further innovation.
In this article we describe and reflect upon a unique example of a group of scientists and art restoration technicians working together to study and treat a piece of colonial art, review some of the applications in biotechnology for the preservation of mankind’s cultural heritage. I predict an expansion in this field and the further development of biotechnological techniques, which will open new opportunities to both biologist and artwork preservers.
La Inmaculada, in the nineteenth century, Alexander Von Humbolt, in his account of trips to equatorial regions of the new continent, marveled at the high level of culture attained by the settlers in the province of Venezuela. One of the few remaining artwork of this culture is a wood carving of the young Immaculate Creole Virgin Mary (La Immaculada). This piece was colonized by wood eating insects and this Infestation inspired a joint effort by local scientists to apply biotechnological techniques, normally used in forensics and agriculture to identify the infectious agents and tailor biological measures to rid the artwork off it. To and the above, reoccurring, this measure must be taken as I will explain below because prevention is better than cure. First for example
IDENTIFYING THE BIOLOGICAL AGENTS THAT CAUSE ARTWORK DESTRUCTION
Apart from pollution, the most common agents causing artwork deterioration are fungi, bacteria, and insects. Identification of the agent responsible is a crucial step in developing a treatment strategy for an infected artwork.
The genome of an organism contains unique variable polymorphic regions which differ between individual and species. Using molecular DNA finger-printing technique, such as ribotyping, these regions can be used to identify an infectious agent even without previous culturing; a useful property when identifying fastidiously growing anaerobic bacteria or slow-growing fungi. DNA typing, however, cannot tell us whether the sample corresponds to a live or dead organism therefore it has to be combined with other technologies, such as ATP consumption or use of biosensor.
One example of a combined approach, although a previous culturing step was performed, is the molecular identification of Hulobacillus populations isolated from a biodegraded wall painting from the 14th century Catherin Chapel in the Castle of Herberstain, Hustila, Pinal, G.el al (2001). Other salt-tolerant bacteria, known as halophiles, responsible for the biodegradation of wall paintings have been identified using such molecular techniques.
In tropical climates many insect species prey on wood and paper and the most common pests are termites of taxonomical order Isoptera, although other groups, such as coleoptera (beetles) and Lepidoptera(carpenter worms) are also prevalent. When termites infest an artwork, their rapid growth makes it relatively easy to spot the infestation. However, member of the Anobildae family (Coleoptera) have long larval period with associated low metabolic activity and very often, infestation pass unnoticed and the sculpture crumbles like a “saline cracker”, Having identified the Biological Agents that cause art work destruction, the following step should be apply to stand against further harm. As such care most be taken to eradicate infestation through this process.
OPTIONS TO ERADICATE THE INFESTATION
The eradication of woodborer infestations is not a simple task especially in the tropics where repeated treatments and perseverance are needed, in treating an affected artwork, Hippocrates's medical rule "primum non noce "first do not harm", should be followed.
In enclosed museum environments control of fungal infections is generally accomplished by reducing air humidity; however this approach is not easy to apply in an open environments because of their high toxicity and the potential to cause harm to the artwork, the use of biocides is not recommended.
Furthermore, physical treatments, such as ultrasonic microwaves, electromagnetic shocks of low current, high frequency and highs voltage, freezing or heating are not recommended because most paint materials and wood textures can be altered by such treatments. Two innocuous alternatives to the above are fungicide and bioactive peptides, which are both easily degraded and do not threaten the artwork.
Antibiotics and peptides can also be used on bacterial infections.
Although less effective for fungal control, oxygen depletion has proven to be a successful approach for controlling insect infestations in artworks, where appropriate. Despite being harmless, this technique, in its original version, requires cumbersome and costly equipment and long treatment periods. Recently, cheaper softcase have considerably reduced the cost of this technology. One disadvantage of using oxygen depletion is that some insects (and their eggs) can live for long periods, under hypoxic conditions by reverting to anaerobic metabolism, h addition, this treatments does not prevent reinfestations by the same bug.
An alternative to physical or chemical method is biological control, which is widely used in agriculture to control pest. This method involves the use of either parasitic insect that prey on other insects, enthomopathogenic fungi, or bacteria and viruses that kill other bugs. The most commonly used bacterium is Bacillus thuringiensis (BT), which produce a repertoire of toxins able to kill more than a thousand insect species, and some BT subspecies have been described.
In Conclusion
The experience with La Inmaculada and the other Examples given in this article quoted here illustrates the potential use of biotechnology in preservation of our cultural heritage. Biotechnological techniques are powerful, environmentally friendly, low cost and present low-risk to human health. If this method can be embraced in Nigeria Museum, the Nigerian Museum will be among other museums in a developing Country that have embarked on biotechnological method of conservation.
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