## 4 Conclusions  
In the present study, we evaluated the potential use of Cymbopogon citratus, Lavandula angustifolia, Thapsia gummifera, Mentha pulegium, Mentha sauveolens, Thapsia villosa, Thymus mastichina and Agastache foeniculum volatilized EOs obtained by hydrodistillation as tools for the control of fungal contamination and biodeterioration in cultural heritage. Cymbopogon citratus and L. angustifolia EOs showed the strongest inhibitory effects on the isolates obtained from sampling a museum collection showing clear signs of fungal contamination, with the EOs being able to fully inhibit fungal growth of all eight fungal species tested at at least one of the four tested concentrations (0.5, 1, 1.5 and 2 \(\mu\)L cm\({}^{-3}\)). And while both Mentha EOs were found to have varied degrees of success, the remaining EOs (Thapsia villosa, T. gummifera, T. mastichina and A. foeniculum) were not observed to have an impact on fungal growth. Of the eight fungal isolates tested, _Penicillium brevicompactum_ and _Trichoderma longibrachatum_ were observed to be the most resistant to the tested treatments, even for the most effective EOs, which is of particular concern given their fibrinolytic, cellulolytic and proteolytic properties. Nevertheless, one or more concentrations of _C. citratus_ and _L. angustifolia_ EOs were effective in inhibiting their growth. Although further research is needed to evaluate the compatibility of the proposed treatments with the artifacts and to develop delivery methods and technologies, the resultsfrom this work indicate that volatilized EOs are a natural and effective alternative for the control of fungi-related biodeterioration processes affecting cultural heritage objects. Conceptualization, L.F., C.C., A.P. and N.M.; methodology, L.F., D.P., E.P., A.C.R., E.L., M.P.M. and C.C. ; software, L.F. and D.S.P. ; validation, L.F., C.C., A.P. and N.M.; formal analysis, L.F. and N.M.; investigation, L.F., D.P., E.P., A.C.R., E.L., M.P.M. and C.C. ; resources, C.C., A.P. and N.M.; data curation, L.F.; writing--original draft preparation, L.F.; writing--review and editing, L.F., D.S.P., A.C.R., M.P.M., C.C., A.P. and N.M.; visualization, L.F. and N.M.; supervision, C.C., A.P. and N.M.; project administration, N.M.; funding acquisition, N.M. All authors have read and agreed to the published version of the manuscript. This work was funded by Foundation for Science and Technology (FCT, Portugal), through the following projects: UIDB/04004/2025: Centre for Functional Ecology, Associate Laboratory TERRA (LA/P/0092/2020--DOI: 10.54499/LA/P/0092/2020), UIDB/04539/2020--DOI: 10.54499/UIDB/04539/2020, UIDP/04539/2020--DOI: 10.54499/UIDP/04539/2020, LA/P/0058/2020--DOI: 10.54499/UIDP/04539/2020; ANOXYOILS project: 202.07967.PTDC; and CoaMedPlants project: COA/BRB/0019/2019--DOI: 10.54499/COA/BRB/0019/2019. This work was also supported by \"Projetos Semente de Investigacio\", awarded by Santander Universidades, the University of Coimbra and the Institute of Interdisciplinary Research. [PERSON] is supported by the IT137-23-290 scholarship, under the 2022.07967.PTDC project. [PERSON] is supported by a PhD research grant with reference UI/BD/150843/2021 awarded by the Centre for Functional Ecology--Science for People & the Planet (CFE) and co-funded by Fundacao para a Ciencia e Tecnologia, I.P. (FCT) through national funding by the Ministerio da Ciencia, Tecnologia e Ensino Superior (MCTES) from Fundo Social Europeu (FSE). [PERSON] is supported by a Foundation for Science and Technology (FCT) PhD grant (Reference: PRT/BD/154364/2022). [PERSON] is supported by a Foundation for Science and Technology (FCT) PhD grant (Reference: PRT/BD/153391/2021). These PhD grants are funded by the national budget and co-financed through the European Social Fund (ESF) and the Regional Operational Por_Centro. [PERSON] is funded through national funds (OE) and the Foundation for Science and Technology (FCT, Portugal), in the scope of Decree-Law 57/2016.