Evaluating the Biodeterioration Enzymatic Activities of Fungal Contamination Isolated from Some Ancient Yemeni Mummies Preserved in the National Museum

Abstract

Sophisticated mummification using chemical preservation was prevalent in ancient Yemeni civilization as noted in the 4th century B.C. mummies of the National Museum of Yemen, Sana'a, used in this study. Five of these mummies were used to evaluate hydrolytic enzymes produced as a result of fungal contamination. Forty-seven fungal species were isolated, thereby reflecting a high degree of contamination which may have resulted from the poor ventilation and preservation system. Aspergillus was the most common genus isolated (48.9%). Fifteen isolates exhibited ability to produce cellulase (EC; 3.2.1.4), Aspergillus candidus being the highest cellulose-producer. Pectin lyase (PL, EC; 4.2.2.2) and pectin methyl esterase (PME, EC; 3.1.1.11) were produced by Trichoderma hamatum, whereas chitinase (EC; 3.2.1.14) was produced by Aspergillus niger. Protease activity was noted by only Cladosporium herbarum. The higher activities of these fungal hydrolytic enzymes represent the major threats of biodeterioration including deteriorating linen bandages as well as the mummy bodies. Therefore, it is recommended to improve the preservation system of the mummies at the National Museum to minimize the contamination up to the lowest level and protect the mummies from biodeterioration.

Detection of potential biodeterioration risks for tempera painting in 16th century exhibits from State Tretyakov Gallery

“…6 Fig). U. chartarum is well known to be involved in biodeterioration of organic and inorganic substrates; it can invade surfaces containing very little substrate, thus posing a risk of degradation for various materials, including cultural artifacts [42,43]. In our study, U. chartarum demonstrated growth inside CD agar and mock layers (S9 and S11 Figs), suggesting its possible role in biodeterioration of tempera painting.…”

Two new cellulolytic fungal species isolated from a 19th-century art collection

“…The most prevalent genus was Cladosporium . Of the nine identified genera, Aspergillus , Chaetomium, Cladosporium , Penicillium , and Trichoderma are reported as common microbiota in ancient works of art 1 , 2 , 17 , 30 , 31 . The actin region was sequenced to confirm the results obtained with the ITS region, and to classify to species level some samples that could not be done with ITS.…”

“…Assay of the cellulase activity showed that 95% of the samples produce extracellular enzymes that break down cellulose into smaller oligosaccharides or monosaccharides, as evident from the clear zone observed after staining the plates with Gram’s iodine (see Table 2 and Supplementary Figure S4 ). This fraction that includes the two new species (sample #19: Periconia epilithographicola and sample #21: Coniochaeta cipronana ) also comprehends species of Arthrinium, Aspergillus, Chaetomium, Cladosporium, Colletotrichum, Penicillium , and Trichoderma , being the first four commonly reported with cellulolytic activity 31 , 39 – 45 . These observations are congruent with the habitat of restricted carbon sources, in which sheets or laminae made of fibers of cellulose pulp were the support material for the growth of microorganisms.…”

The microbiomes of a XVIII century mummy from the castle of Krásna Hôrka (Slovakia) and its surrounding environment

“…Based on the cultivation strategy, this hydrolytic group, isolated from the mummy surface, is composed of members of the genera Bacillus , Micrococcus , Alternaria , Cladosporium , Penicillium and of the species A. pullulans and E. nigrum . The presence of such microorganisms is consistent with the findings of previous works, where the hydrolytic properties of isolates from historical objects or mummy‐related samples were investigated (Mesquita et al ., ; Kraková et al ., ; Naji et al ., ; Piñar et al ., ; Šimonovičová et al ., ).…”

“…This culture‐independent approach was also able to detect high abundances of other fungal taxa. Some of these have previously been isolated from mummified human remains, for example Aspergillus and Talaromyces, which also exhibited biodegradative potential (Naji et al ., ; Šimonovičová et al ., ). The occurrence of Metarhizium , an entomopathogenic fungus (Greenfield et al ., ), is likely associated with the presence of the different insects that colonized the mummified body.…”