Microbial destruction of optical and electronic materials has been studied. Contamination of materials by microorganisms may be an issue for unattended and space-based optical and electronic systems. We have investigated the process of growth and distribution of fungal elements of Aspergillus flavus and Aspergillus niger, on materials that were inoculated by spores at concentrations 2.5x106, 2.15x103 spores/mL. Different optical dielectric materials, including photorefractive crystal of LiNbO3 crystals (LN), photosensitive polymers PMMA, doped with phenantrenequinone (PQ), and sapphire were used. It was found that spores on LiNbO3:Fe under the same environmental conditions (temperature, humidity) germinated faster and growth of hyphal strands were more elongated and more evenly dispersed than on other materials. Our preliminary interpretation of the observed data is based on the influence of the space-charge fields (observed on the surface of LN) on fungal growth. Illuminating LN crystals by space-structured light showed the possibility of controlled redistribution of microorganisms (E-coli bacteria) on the crystal surface.
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