Cappitelli Francesca, Principi Pamela, Pedrazzani Roberta, Toniolo Lucia, Sorlini Claudia
Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, University of Milan, Via Celoria 2, 20133 Milan, Italy.
Sci Total Environ. 2007 Oct 15;385(1-3):172-81. doi: 10.1016/j.scitotenv.2007.06.022. Epub 2007 Jul 20.
Surfaces are continuously exposed to physical, chemical and biological degradation. Among the biological agents that cause deterioration, microorganisms are of critical importance. This work is part of a research programme for the characterisation of the alterations of the Milan Cathedral (Italy). Four stone samples of the Milan Cathedral were chemically analysed and the microbiological growth assessed. X-ray diffraction (XRD) showed that calcite was always present in each sample and one sample was also characterised by the chemical form of alteration gypsum. Using Fourier Transform Infrared Spectroscopy (FTIR) together with Scanning Electron Microscopy (SEM), it was possible to prove that the samples were consolidated with the synthetic acrylics and epoxy resins. The green-black biological patinas of the specimens were studied using cultivation, microscope observations and a method for single-cell detection. Sampling for fluorescent in-situ hybridisation (FISH), with ribosomal RNA targeted oligonucleotide probes, was also performed using adhesive tapes. The bulk of the prokaryotes were Bacteria but some Archaea were also found. The bacterial cells were further characterised using specific probes for Cyanobacteria, and alpha-, beta-and gamma-Proteobacteria. In addition, black fungi isolated from the stone and the fungi of the standard ASTM G21-96(2002) method were employed to test if the detected synthetic resins could be used as the sole source of carbon and energy. One isolated Cladosporium sp. attacked the freshly dried acrylic resin. Results show that the detected bacteria and fungi can cause severe damage both to the stone monument and its synthetic consolidants.
物体表面不断受到物理、化学和生物降解作用的影响。在导致材料劣化的生物因素中，微生物至关重要。本研究是意大利米兰大教堂材料变化特征研究项目的一部分。对米兰大教堂的四块石材样本进行了化学分析，并评估了微生物的生长情况。X射线衍射（XRD）表明，每个样本中均始终存在方解石，且有一个样本还呈现出蚀变石膏的化学形态特征。利用傅里叶变换红外光谱（FTIR）和扫描电子显微镜（SEM），证实了样本使用合成丙烯酸树脂和环氧树脂进行了加固处理。通过培养、显微镜观察和单细胞检测方法对样本的绿黑色生物锈层进行了研究。还使用胶带对样本进行了荧光原位杂交（FISH）采样，所用的核糖体RNA靶向寡核苷酸探针。原核生物主要是细菌，但也发现了一些古细菌。利用针对蓝细菌以及α-、β-和γ-变形菌的特异性探针进一步对细菌细胞进行了表征。此外，从石材中分离出的黑曲霉以及按照标准ASTM G21-96(2002)方法培养的真菌，用于测试检测到的合成树脂是否可作为唯一的碳源和能源。分离出的一种枝孢菌属攻击了新干燥的丙烯酸树脂。结果表明，检测到的细菌和真菌会对石碑及其合成加固剂造成严重破坏。
