Essential oils as alternative biocides for the preservation of waterlogged archaeological wood
Author(s)
Date Issued
2020
Type
article
Journal
Abstract
microorganisms
Article
Essential Oils as Alternative Biocides
for the Preservation ofWaterlogged
ArchaeologicalWood
Federica Antonelli 1,* , Marco Bartolini 2, Marie-Laure Plissonnier 3 , Alfonso Esposito 4 ,
Giulia Galotta 2, Sandra Ricci 2, Barbara Davidde Petriaggi 5 , Cristian Pedone 6,
Antonella Di Giovanni 6, Silvano Piazza 4,7 , Francesca Guerrieri 3,*,y
and Manuela Romagnoli 1,y
1 Department for Innovation in Biological, Agro-Food and Forestry Systems (DIBAF), Tuscia University,
01100 Viterbo, Italy; mroma@unitus.it
2 Biology Laboratory, Istituto Centrale per il Restauro (ICR), Ministry of Cultural Heritage and Activities
and Tourism (MIBACT), 00153 Rome, Italy; marco.bartolini@beniculturali.it (M.B.);
giulia.galotta@beniculturali.it (G.G.); sandra.ricci@beniculturali.it (S.R.)
3 Epigenetics and Epigenomic of Hepatocellular Carcinoma, U1052, Cancer Research Center of Lyon (CRCL),
69424 Lyon CEDEX 03, France; marie-laure.plissonnier@inserm.fr
4 Department of Cellular, Computational and Integrative Biology–CIBIO, University of Trento,
38123 Trento, Italy; alfonso.esposito@unitn.it (A.E.); silvano.piazza@icgeb.org (S.P.)
5 Underwater Archaeological Operations Unit, Istituto Centrale per il Restauro (ICR), Ministry of Cultural
Heritage and Activities and Tourism (MIBACT), 00153 Rome, Italy; barbara.davidde@beniculturali.it
6 Restoration Laboratory of Organic Excavation Materials, Istituto Centrale per il Restauro (ICR),
Ministry of Cultural Heritage and Activities and Tourism (MIBACT), 00153 Rome, Italy;
cristianpedone95@hotmail.com (C.P.); antonella.digiovanni@beniculturali.it (A.D.G.)
7 Computational Biology, International Centre for Genetic Engineering and Biotechnology, 34149 Trieste, Italy
* Correspondence: fedantonelli@gmail.com (F.A.); francesca.guerrieri@inserm.fr (F.G.)
y Authors contributed equally.
Received: 19 October 2020; Accepted: 14 December 2020; Published: 16 December 2020
Abstract: Waterlogged archaeological wood is exposed to a high risk of biological degradation
during the post-excavation phases of storage and restoration. For this reason, often biocides must
be used to preserve wooden remains. In the present work three essential oils (cinnamon, wild
thyme, and common thyme) were tested as possible alternative biocides to use in the preservation
of waterlogged archaeological wood. The oils were first tested in vitro to establish the minimum
inhibitory concentration (MIC) and to evaluate the biocidal activity on selected fungal strains. Then,
the established MIC was applied on waterlogged archaeological wood samples and during an actual
restoration treatment. The e ectiveness of the oils was evaluated through cultural analyses, ATP
quantification, and next-generation sequencing. The results showed that the oils caused a significant
decrease in the vitality of fungal mycelia grown in vitro and of the microbiota present in treated wood
and storage water. Furthermore, an influence on the composition of the bacterial communities of
treated wood samples was observed. Although further tests are needed to evaluate interferences
with the materials used during restoration procedures, essential oils could be considered as a possible
alternative to the currently used biocide.
Keywords: cinnamon; wild thyme; common thyme; cultural analyses; ATP bioluminescence; NGS;
minimum inhibitory concentration (MIC);WAW; archaeological wood biodegradation; archaeological
wood restoration
Microorganisms 2020, 8, 2015; www.mdpi.com/journal/microorganisms
Subjects