Fungal melanins that deteriorate paper cultural heritage: An overview

Paper-based works of art and documents of cultural importance kept in museums and libraries can show notorious signs of deterioration, including foxing stains, caused by fungal colonization. Some of the main chromophore agents of fungal origin that deteriorate paper and therefore affect paper cultural heritage both aesthetically and structurally are the group of pigments called melanins. Thus, knowledge of the diversity and features of fungal melanins and of the melanization pathways of fungi growing on paper is key to removing these pigments from paper-based works of cultural importance. This review provides an approach about the current knowledge of melanins synthesized by paper-colonizing fungi, their localization in the fungal structures, and their role in the deterioration of paper. This knowledge might contribute to developing new, effective, and sustainable strategies of restoration and conservation of historical documents and works of art based on paper.馆藏于博物馆与图书馆的纸质艺术品及具有文化价值的文献，常出现显著的劣化迹象，其中便包括由真菌定殖引发的纸张褐斑点污斑（foxing stains）。部分可对纸张造成劣化、进而从美学与结构层面损害纸质文化遗产的主要真菌源性生色团物质，为一类被称为黑色素（melanins）的色素。因此，明晰真菌黑色素的多样性与特性，以及定殖于纸张的真菌的黑色素合成途径，是从具有文化价值的纸质艺术品及文献中去除此类色素的核心关键。本综述系统梳理了当前关于定殖于纸张的真菌所合成的黑色素、这类黑色素在真菌结构中的定位分布，以及其在纸张劣化过程中所扮演的角色的相关认知。这类认知或可为开发新型高效且可持续的纸质历史文献与艺术品修复保护策略提供重要支撑。