Michaelsen Astrid, Pinzari Flavia, Barbabietola Nicoletta, Piñar Guadalupe
Department of Microbial Ecology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
Int Biodeterior Biodegradation. 2013 Oct;84(100):333-341. doi: 10.1016/j.ibiod.2012.08.005.
Fungi are among the most degradative organisms inducing biodeterioration of paper-based items of cultural heritage. Appropriate conservation measures and restoration treatments to deal with fungal infections include mechanical, chemical, and biological methods, which entail effects on the paper itself and health hazards for humans. Three different conservation treatments, namely freeze-drying, gamma rays, and ethylene oxide fumigation, were compared and monitored to assess their short- (one month, T1) and long-term (one year, T2) effectiveness to inhibit fungal growth. After the inoculation with fungi possessing cellulose hydrolysis ability - , and - as single strains or as a mixture, different quality paper samples were treated and screened for fungal viability by culture-dependent and -independent techniques. Results derived from both strategies were contradictory. Both gamma irradiation and EtO fumigation showed full efficacy as disinfecting agents when evaluated with cultivation techniques. However, when using molecular analyses, the application of gamma rays showed a short-term reduction in DNA recovery and DNA fragmentation; the latter phenomenon was also observed in a minor degree in samples treated with freeze-drying. When RNA was used as an indicator of long-term fungal viability, differences in the RNA recovery from samples treated with freeze-drying or gamma rays could be observed in samples inoculated with the mixed culture. Only the treatment with ethylene oxide proved negative for both DNA and RNA recovery. Therefore, DNA fragmentation after an ethylene oxide treatment can hamper future paleogenetic and archaeological molecular studies on the objects.
真菌是导致文化遗产纸质物品生物劣化的最具降解能力的生物之一。应对真菌感染的适当保护措施和修复处理包括机械、化学和生物方法，这些方法会对纸张本身产生影响并对人类健康构成危害。比较并监测了三种不同的保护处理方法，即冷冻干燥、伽马射线和环氧乙烷熏蒸，以评估它们抑制真菌生长的短期（一个月，T1）和长期（一年，T2）效果。在用具有纤维素水解能力的真菌（-、-和-，作为单一菌株或混合菌株）接种后，对不同质量的纸样进行处理，并通过依赖培养和不依赖培养的技术筛选真菌活力。两种策略得出的结果相互矛盾。在用培养技术评估时，伽马辐射和环氧乙烷熏蒸作为消毒剂均显示出完全的效果。然而，当使用分子分析时，伽马射线的应用显示出DNA回收率短期下降和DNA片段化；在用冷冻干燥处理的样品中也在较小程度上观察到了后一种现象。当RNA用作长期真菌活力的指标时，在用混合培养物接种的样品中，可以观察到冷冻干燥或伽马射线处理的样品在RNA回收率上的差异。只有环氧乙烷处理对DNA和RNA回收率均呈阴性。因此，环氧乙烷处理后的DNA片段化可能会妨碍未来对这些物品进行古遗传学和考古学分子研究。
