BIOLOGICAL CULTURES

Studies the nature and growth of micro- and macro-organisms on bio-deteriorated materials.

WHAT IS IT FOR

dating

morphology

technology

origin

composition

alteration

APPLICABLE MATERIALS

Ceramic

Glass

Metal

Mortar

Pigments

Stone

Wood

Ceramic Building Materials (CBM),Glass, Metals & Alloys, Mortar & Plaster, Stone, Pigments, Wood
Biological cultures aim at studying the nature and growth-pattern of biodeteriogens growing on historic building materials and monitoring the factors that encourage colonization, which include temperature, rain, shadow, sun, organic/inorganic pollutants, bioreceptivity* of the colonized material, etc. Moreover, the method is useful in order to estimate whether and how they are responsible for a material’s damage, to develop a sequence that aims at recovering the structural “health” of a building material preventing further decay, to evaluate the effi cacy of biocides* and to facilitate long-term monitoring treated materials.

BRIEF DESCRIPTION

Table and diagram of colony-forming unit (CFU) per petri dish. Biodeterioration analysis in the Fuente Nuevaof Martos (Jaen) within te Martos Porject 2012 (DIADRASIS)

Biological cultures allow the identification of the nature and observe the growth-pattern of micro- and macro-organisms in order to defi ne the type and degree of microbially induced damage.(Micro) Biological culture is the procedure consisting of reproducible growth of microbial cultures in defined physical and chemical environmental conditions.

Table and diagram of colony-forming unit (CFU) per petri dish. Biodeterioration analysis in the Fuente Nuevaof Martos (Jaen) within te Martos Porject 2012 (DIADRASIS)

Metrics

accuracy
time
cost

Sampling

in situ

invasive

destructive

TIPS

Use the method to identify the biodeteriogens on building materials and to distinguish atmospheric deposits from biological colonizations
Sampling is preferably performed where microbial growth is extensive

Advantages

standardized analysis
fast
accurate qualitative results

Limitations

in-depth microbial growth complicates extraction and sampling

HOW DOES IT WORK?

There are several different types of growth media, generally containing a mixture of sugars and complex polysaccharides, carbohydrates, proteins, amino acids, lipids, water, urea, salts, trace elements (e.g. Iron, Copper, Magnesium, Potassium), vitamins, etc. In order to identify and characterize microbial species, it is necessary to obtain them in pure cultures, by spreading them out and permitting the individual cells to form colonies. Microbiological cultures are usually grown by means of two techniques:

- Culture plates: sterilized petri dishes* containing an agar*-based growth medium.
- Liquid culture: microbial cultures can be grown in a small volume flask or in test tubes containing nutrients in a liquid medium.

N.B. For anaerobic microorganisms*, the atmosphere must be oxygen free.

References

Nair, J., 2008. Microbial Culture and Applications. In: Introduction to Biotechnology and Genetic Engineering, Hingham, Massachusetts - New Delhi, India: Infi nity Science Press LLC, pp. 545- 551. [online] Available at https://thunderbooks.fi les.wordpress.com/2009/05/introduction-tobiotechnology- and-genetic-engineering-infi nity-2008.pdf [Accessed 20 May 2015].
Kigawa, R., Sano, C., Nishijima, M., Tazato, N., Kiyuna, T., Hayakawa, N., Kawanobe, W., Udagawa, S., Tateishi T., Sugiyama, J., 2013. Investigation of acetic acid bacteria isolated from the Kitora tumulus inJapan and their involvement in the deterioration of the plaster of the mural paintings. Studies in Conservation Vol. 58, No. 1, pp. 30-39.
Pinna, D., 2007. Sampling of biodeteriogens in monumental and archaeological areas - methods and usefulness. In: Atti del Convegno “Small samples, big objects”, München: Bayerishes Landesamt fur Denkmalpfl ege, pp. 96-104.