In Vitro Evaluation of MgB2 Powders as Novel Tools to Fight Fungal Biodeterioration of Heritage Buildings and Objects

Abstract

The 17th–19th century wooden and stone churches are an iconic symbol for the Romanian national heritage, raising urgent needs for the development of efficient and ecofriendly restoration and preservation solutions. Nanotechnology has a great but largely unexplored potential in this field, providing new tools and methods to achieve higher consolidation and protection efficiency, mainly due to the ability of nanoparticles to inhibit the growth and metabolic activity of different biodeteriorating agents, including fungi. The purpose of the present study was to report for the first time on the efficiency of MgB2 materials, mainly prized for their practical superconducting properties, against a large collection of filamentous fungal strains recently isolated from biodeteriorated wooden and stone heritage objects. Four types of MgB2 powders, with a crystallite size of 42–113 nm, were tested by qualitative (on 149 strains) and quantitative (on 87 strains) assays. The cytotoxicity was evaluated by the microscopic analysis of SiHa cells morphology and Hep2 cell cycle analysis and the ecotoxicity by the Allium test. The tested filamentous fungal strains belonged to 11 different genera, and those isolated from mural paintings and wooden objects exhibited the best capacity to colonize the inert substratum. All MgB2 powders exhibited similar and relatively low minimal inhibitory concentrations (MIC) values against the Aspergillus and Penicillium isolates, which were predominated among isolates. From the tested powders, PVZ and CERAC proved to be more efficient against the strains isolated from stone and wood materials, while LTS was active against the fungal strains colonizing the mural paintings and museum objects. The cytotoxicity results indicated that the tested powders are toxic for the human cells at concentrations higher than 50 µg/ml, but, however, the very short lifetime of these NPs prevents their accumulation in the natural environment and, thus, the occurrence of toxic effects. The tested powders proved to be ecofriendly at the active antifungal concentrations, as suggested by the phytotoxicity test results. Taken together, our results suggest the potential of the MgB2 materials for the development of environmentally safe antifungal substances, which can be used in the control of the material cultural heritage biodeterioration process.

Eco-Friendly Solution Based on Rosmarinus officinalis Hydro-Alcoholic Extract to Prevent Biodeterioration of Cultural Heritage Objects and Buildings

“…After the incubation period (5–7 days at room temperature/24 h at 37 °C), the minimum inhibitory concentration (MIC) values were established as corresponding to the lowest concentration at which the tested plant extract inhibited the growth of the microbial cultures. The final results were calculated and expressed after the solvent inhibitory effect was eliminated [ 92 ].…”

Sampling methods for outdoor sculptures: Comparison of swabs and cryogels by flow cytometry as novel alternatives for assessment and quantification of microbial contamination

“…Flow cytometry has been successfully used over the years in several fields of research, for the analysis of environmental, pharmaceutical, medical and food samples [17,18,27,28,[19][20][21][22][23][24][25][26]. In the context of CH, however, its application is still limited, although some studies have used flow cytometry as a complement to other analytical tools, either in the study of the microorganisms involved in the biodeterioration processes of artworks or the evaluation of the efficiency of potential biocide treatments [29][30][31][32][33][34].…”

Demonstration of Allium sativum Extract Inhibitory Effect on Biodeteriogenic Microbial Strain Growth, Biofilm Development, and Enzymatic and Organic Acid Production

“…In this context, there is an increased necessity to develop effective and ecofriendly prevention and conservation solutions to protect the material cultural heritage against microbial (re)colonization, with low toxicity risk for human, animal, and environmental health [ 11 , 12 ]. Our research group revealed the efficiency of MgB 2 ecofriendly powders against biodeteriogenic fungi isolated from wooden and stone churches and heritage objects from Romanian counties [ 13 ].…”