Essa Ashraf M M, Khallaf Mohamed K
Botany Department, Faculty of Science, Fayoum University, Fayoum, Egypt.
Biology Department, Faculty of Science, Jazan University, Jazan, Saudi Arabia.
BMC Microbiol. 2016 Jul 11;16(1):144. doi: 10.1186/s12866-016-0766-8.
Biodeterioration of historic monuments and stone works by microorganisms takes place as a result of biofilm production and secretion of organic compounds that negatively affect on the stone matrix.
Copper nanoparticles (CuNPs) were prepared biologically using the headspace gases generated by the bacterial culture Escherichia coli Z1. The antimicrobial activity of CuNPs was evaluated against the bacterial strains Bacillus subtilis, Micrococcus luteus, Streptomyces parvulus, Escherichia coli, Pseudomonas aeruginosa as well as some fungal strains Aspergillus niger, Aspergillus flavus, Penicillium chrysogenum, Fusarium solani and Alternaria solani.
Biological CuNPs demonstrated antibacterial and antifungal activities higher than those of the untreated copper sulfate. At the same time, limestone and sandstone blocks treated with consolidation polymers functionalized with CuNPs recorded apparent antimicrobial activity against E. coli, S. parvulus and B. subtilis in addition to an improvement in the physical and mechanical characters of the treated stones. Furthermore, the elemental composition of CuNPs was elucidated using electron dispersive x-ray system connected with the scanning electron microscope.
Consolidation polymers impregnated with CuNPs could be used to restrain microbial deterioration in addition to the refinement of physico-mechanical behavior of the historic stones.
微生物对历史古迹和石雕的生物劣化是由于生物膜的形成以及有机化合物的分泌，这些有机化合物会对石材基质产生负面影响。
利用大肠杆菌Z1细菌培养产生的顶空气体生物制备铜纳米颗粒（CuNPs）。评估了CuNPs对枯草芽孢杆菌、藤黄微球菌、短小链霉菌、大肠杆菌、铜绿假单胞菌等细菌菌株以及黑曲霉、黄曲霉、产黄青霉、茄病镰刀菌和链格孢菌等一些真菌菌株的抗菌活性。
生物CuNPs表现出比未处理的硫酸铜更高的抗菌和抗真菌活性。同时，用CuNPs功能化的固结聚合物处理的石灰石和砂岩块除了改善处理后石材的物理和力学性能外，还对大肠杆菌、短小链霉菌和枯草芽孢杆菌表现出明显的抗菌活性。此外，使用与扫描电子显微镜相连的电子色散X射线系统阐明了CuNPs的元素组成。
浸渍有CuNPs的固结聚合物除了改善历史石材的物理力学性能外，还可用于抑制微生物劣化。
