太原北齐徐显秀墓壁画可培养真菌多样性及危害防治

【背景】原址保护的墓葬壁画普遍存在着有害微生物的威胁,对壁画菌害的长效防治是文物保护领域久未解决的难题。【目的】确定太原北齐徐显秀墓墓道霉变壁画上可培养真菌多样性,分离优势菌株,并筛选长效的生物杀灭剂,为墓葬壁画菌害的抢救性防治提供科学依据。【方法】利用无菌棉签采集壁画表面白色菌丝体样品,使用扫描电子显微镜分析病害菌微观形貌特征;通过培养、分离及纯化获得真菌菌株,运用形态学和分子技术鉴定种属;结合实验室抑菌圈测试和原位杀菌试验,分析不同生物杀灭剂的抑菌圈大小、杀菌后原位可培养微生物浓度以及ATP荧光值差异,以期找到长效的生物杀灭剂。【结果】霉变壁画表面有大量菌丝体并伴有分生孢子,白色菌丝体样品中可培养真菌属于子囊菌门(Ascomycota)的6个属,其中白色侧齿霉菌(Parengyodontium album)相对丰度最高(98.13%),为优势病害菌。经实验室和原位试验筛选评估,确定了双氯酚复配型杀灭剂(0.5%双氯酚+75%乙醇)对该病害真菌杀灭效果最好,在7年连续监测期内未出现病害菌的复发。【结论】白色侧齿霉菌是引起徐显秀墓墓道壁画霉变的主要可培养病害菌;双氯酚复配型杀菌剂用于该病害菌防治的时效性最长;建议后期结合抢救性防治、环境调节和跟踪监测,以达到墓葬壁画微生物危害的长效防控。

The diversity of cultivable fungi on corridor murals and controlling of microbial deterioration in Xu Xianxiu's tomb of Northern Qi dynasty, Taiyuan

Background] The tomb murals preserved at the original sites are generally threatened by the microbial disease, and the long-term controlling of these microorganisms is a long-standing problem in the field of cultural heritage conservation. Objective] we aimed to explore the cultivable fungal diversity on moldy murals of the tomb corridor surfaces, to isolate the dominant fungal strains and screen the long-acting biocides, and provide a scientific support for the control of the mural''s fungal disease of this tomb. Methods] Mural samples with whitish moldy necrosis were carefully collected by sterile swabs. The surface morphology of samples was analyzed by scanning electron microscope (SEM). The culture-dependent method was employed to isolate fungal strains, and combine with molecular techniques for identification, the community composition of fungi was analyzed thereafter. Combined with the laboratory inhibition zone test and the in-situ biocides test, the size of the inhibition zone of different biocides, the in-situ cultivable microbial concentration after biocides application, and the ATP fluorescence values differences were analyzed in order to find a lasting efficacy of the biocides. Results] There were a large amount of mycelia with conidia, the culturable fungi in the white mycelium samples affilliated to the six genera of Ascomycota phylum, the dominant cultivated fungus was Parengyodontium album (98.13%). After screening and evaluation in laboratory and in-situ tests, it is clear that the most effective biocide was dichlorophene compounds (0.5% dichlorophene with 75% ethanol), and no repeated outbreaks of microorganisms occurred during the 7-year consecutive monitoring period. Conclusion] P. album was the dominant cultivable fungi that caused mural moldy at tomb corridor. Dichlorophene compound biocide used in the controlling test of Xu Xianxiu''s tomb mural of Northern Qi dynasty has achieved the longest timeliness of maintenance; and it is recommended to combine the emergency protection, environmental regulation and follow-up monitoring in the future, as a result, to achieve long-term prevention and control of the microbial hazards to the tomb murals.