Identification of Fungal Community Associated with Deterioration of Optical Observation Instruments of Museums in Northern Vietnam

• Main Authors: Cao Cuong Ngo, Quang Huy Nguyen, Thu Hoai Nguyen, Ngoc Tung Quach, Pravin Dudhagara, Thi Hanh Nguyen Vu, Thi Thanh Xuan Le, Thi Thu Hang Le, Thi Thu Hong Do, Van Duc Nguyen, Nam Trung Nguyen, Quyet-Tien Phi
• Format: Article
• Language: English
• Published: MDPI AG 2021-06-01
• Series: Applied Sciences
• Subjects: glass corrosion; biodeterioration; optical instruments; fungal community; <i>Aspergillus</i>; <i>Penicillium</i>
• Online Access: https://www.mdpi.com/2076-3417/11/12/5351

Fungi are the most harmful microorganisms responsible for the deterioration of nonmetallic materials such as glass, polymers, and composites. To date, biological aspects of glass deterioration have been poorly investigated. The present study aimed to evaluate the diversity of the fungal community colonizing eyepieces of binoculars collected from museums of the northern provinces of Vietnam and the biodeterioration effects on accurate glass reproductions. A total of 40 isolates belonging to 14 genera were identified based on internal transcribed spacer (ITS) sequencing, morphological features, and maximum likelihood analysis. The most abundant fungal genera included <i>Aspergillus</i> (43.8%) and <i>Penicillium</i> (31.3%). Among those detected, <i>Byssochlamys</i>, <i>Curvularia</i>, <i>Phomopsis</i>, <i>Coprinellus</i>, <i>Perenniporia</i>, <i>Talaromyces</i>, <i>Pithomyces</i>, <i>Neopestalotiopsis</i>, <i>Trichoderma</i>, <i>Pleospora</i><i>,</i> and <i>Humicola</i> were found for the first time. Of the 40 strains tested, 8 strains showed great organic acid production, and the extent of mycelium covered from 33.6 to 46.24%. Specifically, the highest extracellular polymeric substance production was observed in <i>Byssochlamys spectabilis</i> BXMA1-2 (14.96 g/L), <i>Aspergillus niger</i> BXMA5-2 (12.17 g/L), and <i>Aspergillus ochraceopetaliformis</i> BMLC1-2 (9.89 g/L). Glass biodeterioration experiments revealed that the light transmission through the fungal-treated glasses was decreased by 30–42.2% as compared to the nontreated glass. In addition, the main alterations resulted from hyphal fingerprints and spots, leading to apparent damage and biocorrosion.