The limestone façade of the Alamo shows several areas of biological growth
with black and gray streaks and blotches discoloring the stone. This thesis investigates
the identity of the microorganisms on the stone, using two: DNA identification, and
lab cultures grown from samples of the biofilm. By using both approaches, a better
understanding was gained of the range of organisms present. Through these tests, it
was found that the dominant organism on the limestone is cyanobacteria, of the genus
Chrooccocus. Lab cultures revealed other organisms, including possibly fungi
photobionts and algae.
Through analysis and comparison of historic and contemporary photographs,
patterns of recolonization are investigated. To further understand the effects of the
biocide treatments, cultured samples were treated, and their reactions monitored. To
better understand the possible relationship between the Alamo stone and its colonizing
organisms, physical properties of the stone were investigated. SEM images, Edax
minerology and water absorption were used to characterize the stone.
This study is the first of its kind to investigate Native Texas quarried
architectural limestone. Although studies have been conducted on historic monuments
around the world to identify biological growth, none have focused on Texas limestone.
By using both DNA and lab culture identification, this study adds to a wealth of
investigations of other conservation professionals, applying it to a subject that has not
been studied in this way before. By understanding the colonizing organisms, a
sustainable conservation regimen can be determined. / text
| Identifer | oai:union.ndltd.org:UTEXAS/oai:repositories.lib.utexas.edu:2152/22370 |
| Date | 21 November 2013 |
| Creators | Gallagher, Casey Amber |
| Source Sets | University of Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | electronic |
| Rights | Copyright is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works., Restricted |
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