Thanaa Abatable, Sumayli Mari, El-Shabasy A
The Faculty of Archaeology, Aswan University, Egypt.
Department of Biology, College of Science, Jazan University, P.O. Box. 114, Jazan 45142, Kingdom of Saudi Arabia.
Saudi J Biol Sci. 2024 Jul;31(7):104004. doi: 10.1016/j.sjbs.2024.104004. Epub 2024 May 7.
The inorganic colour layer based on iron oxide is affected by microorganisms (fungi) and leads to its deterioration due to feeding on the mineral elements through the chemical composition of the colour in the presence of a suitable environment (medium). Damage occurs as a result of heavy metal elements being removed from the colour, leading to a defect in the chemical composition and the fading of the colours. The current study showed the effect of the different types of the most common fungi on oil paintings ( and ) after cultivating the different types of fungi and obtaining pure colonies for each fungus separately and conducting a fungal infection on experimental samples with preparing the old techniques, coloured with hematite red and goethite yellow. Each colour is mixed with different proportions of linseed oil (1, 2, 3). They were aged artificially and incubated at a temperature of 26 degrees and examined periodically until the fungi appeared on the surface in the form of colour spots ranging from very dark (severe infestation) to light (low infestation). The change in chemical composition was measured by Raman and EDX analyses of the samples before and after infection. Fungi showed the appearance of spoilage products from metal sulfides and metal carboxylates. The iron oxide ion decreased in both the red and the yellow colours, leading to a change after the fungal infection. Examination of the morphological surface using SEM, USB and measurement of colour change showed the change in the red colour more than the yellow and scattering of green and black colour dots on the surface of the sample. Correlation and Simple Linear Regression were applied for each colour before and after besides both colours together. It was found that these colours appeared around some of the fungal colonies as a result of the activities. Fungal species of some strains reduced Fe to Fe . This provides new insights into the role of microorganisms in the deterioration of painted surfaces.
基于氧化铁的无机色层会受到微生物（真菌）的影响，在合适的环境（介质）中，由于真菌通过颜色的化学成分摄取矿物元素，从而导致其变质。重金属元素从颜色中被去除，导致化学成分出现缺陷，颜色褪色，进而造成损害。当前的研究展示了在分别培养不同类型的真菌并获得每种真菌的纯菌落之后，使用传统技术，用赤铁矿红和针铁矿黄对油画进行真菌感染，不同类型的最常见真菌对油画的影响。每种颜色与不同比例的亚麻籽油（1、2、3）混合。它们经过人工老化，在26摄氏度的温度下培养，并定期检查，直到真菌以从非常深（严重侵染）到浅（轻度侵染）的色斑形式出现在表面。通过对感染前后样品的拉曼光谱和能谱分析来测量化学成分的变化。真菌显示出金属硫化物和金属羧酸盐等变质产物的出现。红色和黄色中的氧化铁离子均减少，导致真菌感染后发生变化。使用扫描电子显微镜、超景深显微镜对形态表面进行检查以及颜色变化测量显示，红色的变化比黄色更明显，并且样品表面有绿色和黑色的色点散布。对每种颜色在感染前后以及两种颜色一起进行了相关性分析和简单线性回归分析。结果发现，由于真菌的活动，这些颜色出现在一些真菌菌落周围。某些菌株的真菌种类将铁还原为亚铁。这为微生物在绘画表面变质中的作用提供了新的见解。
