Biodeterioration of collagen-based cultural relics: A review

Natural collagen-based cultural relics such as parchment and leather are susceptible to the storage environment, including temperature, relative humidity, pollutants, and microorganisms, resulting in the deterioration of the main components of collagen, keratin, tannins, lipids, oils and tanning regents. Significant changes might occur in the appearance, composition and internal structure, accompanied by the impaired physical properties such as thermal stability, flexibility, and tensile strength. Biodeterioration is one of the main factors affecting the long-term storage of parchment and leather artifacts, particularly in environments with high relative humidity, due to the proliferation and growth of bacteria or fungi. This review focuses on the common microbial communities on the parchment and leather artifacts. The biodeterioration mechanism is discussed, which will shed light onto the future research of collagen-based cultural relics.