Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 13-21 |
| Seitenumfang | 9 |
| Fachzeitschrift | Biotechnology and Bioengineering |
| Jahrgang | 80 |
| Ausgabenummer | 1 |
| Publikationsstatus | Veröffentlicht - 9 Aug. 2002 |
Abstract
A new, gentle enzymatic method was developed for a controlled removal of casein layers from medieval wall paintings. These casein layers were applied over the last 60 years on wall paintings in order to decrease substantial damage due to a peeling off of the frescoes from the roughcast surface due to environmental effects. However, due to the aging of the casein layers (at 40-50 years), a more drastic peeling occurred and the danger of total destruction of the wall paintings is severe. Thus, screening was performed to find the most suitable enzyme for casein digestion. Alcalase 2.5 DX L was the most appropriate enzyme for an effective proteolysis reaction. The enzyme was immobilized on functionalized cellulose membrane. A membrane pad system with immobilized enzymes was developed which could be pressed on the casein layers on the wall painting. A controlled removal of the casein layers by proteolytic digestion was observed and it was possible to continuously wash off the hydrolyzed casein fragments from the wall painting surface by an aqueous carbonate buffer flowing through the membrane pad. The removal and the digestion was monitored by reverse HPLC. Additionally, an on-line monitoring system was set up in order to continuously follow the casein layer removal and the digestion procedure directly on the wall painting. This technique is based on noninvasive 2D-fluorescence monitoring. Optical fiber systems were used to continuously monitor the fluorescence intensity of casein-bound tryptophan. The off-line data were verified with the on-line 2D-fluorescence data. Based on the scientific result an appropriate technique for the controlled enzymatic removal of damaging casein layers on the surface of medieval wall paintings using immobilized enzyme is now available. It is now applied to remove such casein layers from medieval wall paintings in the Allerheiligen-Kapelle Cloister, Wienhausen, Germany, and the St. Alexander Kirche, Wildeshausen, Germany.
ASJC Scopus Sachgebiete
- Biochemie, Genetik und Molekularbiologie (insg.)
- Biotechnologie
- Chemische Verfahrenstechnik (insg.)
- Bioengineering
- Immunologie und Mikrobiologie (insg.)
- Angewandte Mikrobiologie und Biotechnologie
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in: Biotechnology and Bioengineering, Jahrgang 80, Nr. 1, 09.08.2002, S. 13-21.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Controlled Enzymatic Removal ofDamaging Casein Layers on Medieval Wall Paintings
AU - Beutel, Sascha
AU - Klein, Kerstin
AU - Knobbe, Gabi
AU - Königfeld, Peter
AU - Petersen, Karin
AU - Ulber, Roland
AU - Scheper, Thomas
PY - 2002/8/9
Y1 - 2002/8/9
N2 - A new, gentle enzymatic method was developed for a controlled removal of casein layers from medieval wall paintings. These casein layers were applied over the last 60 years on wall paintings in order to decrease substantial damage due to a peeling off of the frescoes from the roughcast surface due to environmental effects. However, due to the aging of the casein layers (at 40-50 years), a more drastic peeling occurred and the danger of total destruction of the wall paintings is severe. Thus, screening was performed to find the most suitable enzyme for casein digestion. Alcalase 2.5 DX L was the most appropriate enzyme for an effective proteolysis reaction. The enzyme was immobilized on functionalized cellulose membrane. A membrane pad system with immobilized enzymes was developed which could be pressed on the casein layers on the wall painting. A controlled removal of the casein layers by proteolytic digestion was observed and it was possible to continuously wash off the hydrolyzed casein fragments from the wall painting surface by an aqueous carbonate buffer flowing through the membrane pad. The removal and the digestion was monitored by reverse HPLC. Additionally, an on-line monitoring system was set up in order to continuously follow the casein layer removal and the digestion procedure directly on the wall painting. This technique is based on noninvasive 2D-fluorescence monitoring. Optical fiber systems were used to continuously monitor the fluorescence intensity of casein-bound tryptophan. The off-line data were verified with the on-line 2D-fluorescence data. Based on the scientific result an appropriate technique for the controlled enzymatic removal of damaging casein layers on the surface of medieval wall paintings using immobilized enzyme is now available. It is now applied to remove such casein layers from medieval wall paintings in the Allerheiligen-Kapelle Cloister, Wienhausen, Germany, and the St. Alexander Kirche, Wildeshausen, Germany.
AB - A new, gentle enzymatic method was developed for a controlled removal of casein layers from medieval wall paintings. These casein layers were applied over the last 60 years on wall paintings in order to decrease substantial damage due to a peeling off of the frescoes from the roughcast surface due to environmental effects. However, due to the aging of the casein layers (at 40-50 years), a more drastic peeling occurred and the danger of total destruction of the wall paintings is severe. Thus, screening was performed to find the most suitable enzyme for casein digestion. Alcalase 2.5 DX L was the most appropriate enzyme for an effective proteolysis reaction. The enzyme was immobilized on functionalized cellulose membrane. A membrane pad system with immobilized enzymes was developed which could be pressed on the casein layers on the wall painting. A controlled removal of the casein layers by proteolytic digestion was observed and it was possible to continuously wash off the hydrolyzed casein fragments from the wall painting surface by an aqueous carbonate buffer flowing through the membrane pad. The removal and the digestion was monitored by reverse HPLC. Additionally, an on-line monitoring system was set up in order to continuously follow the casein layer removal and the digestion procedure directly on the wall painting. This technique is based on noninvasive 2D-fluorescence monitoring. Optical fiber systems were used to continuously monitor the fluorescence intensity of casein-bound tryptophan. The off-line data were verified with the on-line 2D-fluorescence data. Based on the scientific result an appropriate technique for the controlled enzymatic removal of damaging casein layers on the surface of medieval wall paintings using immobilized enzyme is now available. It is now applied to remove such casein layers from medieval wall paintings in the Allerheiligen-Kapelle Cloister, Wienhausen, Germany, and the St. Alexander Kirche, Wildeshausen, Germany.
KW - 2D-fluorescence analysis
KW - Alcalase® 2.5 DX L
KW - Casein
KW - Medieval wall painting
KW - Noninvasive surface analysis
KW - Proteolysis
KW - RPHPLC
KW - Surface layer
KW - Tryptophan
UR - http://www.scopus.com/inward/record.url?scp=0037026930&partnerID=8YFLogxK
U2 - 10.1002/bit.10341
DO - 10.1002/bit.10341
M3 - Article
C2 - 12209782
AN - SCOPUS:0037026930
VL - 80
SP - 13
EP - 21
JO - Biotechnology and Bioengineering
JF - Biotechnology and Bioengineering
SN - 0006-3592
IS - 1
ER -