A method based on the use of electromagnetic radiation (EMR) in the radiofrequency band was experimented to eliminate heterotrophic organisms from biofilms encrusting linen canvasses used for paintings. Artificial biofilms were used for exposure to EMR. Biofilms were grown on fragments of canvasses sampled from the backside of a painting. The fragments, after sterilization, were inoculated with several heterotrophic microorganisms previously isolated from other canvasses used for paintings and identified by molecular analyses as the bacteria Bacillus mycoides and Bacillus subtilis, and the microfungi Aspergillus versicolor, Cladosporium cladosporioides, Cladosporium oxysporum and Fusarium oxysporum . The newly formed biofilms resulted to contain the same microorganisms used for the inocula. They were exposed to EMR obtained by an amplitude-modulating radiofrequency sine wave with a train of rectangular pulses with 200 ns repetition time and 10% duty cycle. The exposure protocol consisted of three applications of two hours each, every other day. Denaturing gradient gel electrophoresis analyses carried out on the EMR-treated biofilms showed that all the microorganisms disappeared after the third application. The amplitude of the adopted EMR was not high enough to cause any significant increase in the temperature of the substrates. Therefore, the methodology showed to be non-invasive for the artefacts and its exposure levels not hazardous for operators and the environment compared to other techniques adopted in the field of conservation of cultural heritage. Among the latter techniques, the most common one is based on the use of biocides that, although effective, present problems in all the above-described areas.

中文翻译：

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使用射频电磁辐射去除画布上的生物膜

实验了一种基于在射频频带中使用电磁辐射 (EMR) 的方法，以从覆盖用于绘画的亚麻帆布的生物膜中消除异养生物。人工生物膜用于暴露于 EMR。生物膜生长在从画作背面取样的画布碎片上。消毒后的碎片用几种异养微生物接种，这些微生物以前从用于绘画的其他画布中分离出来，并通过分子分析鉴定为细菌丝状芽孢杆菌和枯草芽孢杆菌，以及微真菌花曲霉、枝状枝孢菌、尖孢枝孢菌和尖孢镰刀菌。新形成的生物膜含有与接种物相同的微生物。他们暴露于 EMR 中，该电磁波通过幅度调制射频正弦波获得，其中包含一系列矩形脉冲，重复时间为 200 ns，占空比为 10%。暴露协议由三个应用组成，每次两个小时，每隔一天。对经 EMR 处理的生物膜进行的变性梯度凝胶电泳分析表明，第三次应用后所有微生物都消失了。所采用的 EMR 的幅度不足以引起基板温度的任何显着增加。因此，与文化遗产保护领域采用的其他技术相比，该方法对文物是非侵入性的，其暴露水平对操作者和环境无害。在后一种技术中，