The current research project was established to verify the mechanisms of fungal deterioration and the efficiency of fungal control methods used in museums as a serious problem that faces those who are working in the field of museum collection management. The project includes six main chapters as follow:
The first chapter of the thesis is "Introduction". Textiles are an important source of reference for the cultural studies since they represent a significant aspect of craft manifestation directly correlated to people’s culture. The majority of ancient Egyptian textiles are of linen which was made from flax. Contamination of textile objects presented in exhibition rooms or stored in depots and their spoilage by fungi is nowadays a significant problem for cultural heritage conservator. The beneficial measures to avoid fungal contamination in cultural institutions are strongly required. The individual use of each control method in museums cannot fittingly eradicate such problem. Thus, some modifications of the treatment techniques is required for gaining suitable way for controlling fungal contamination in museums.
The second chapter of the thesis, "Microbiological, morphological and spectroscopic study on the effect of resinous materials in the preservation of wrapping textiles of mummies" includes the isolation of several fungal strains from ancient linen textile samples of mummies wrappings; evaluation the fungal deterioration of ancient samples; and evaluation the role of one of ancient Egyptian additives materials (resinous materials) on protection of the wrapping textile from environmental factors (especially microorganisms). The tested ancient samples were characterized depending on the resinous materials adherent with their fibers. The previous studies stated that the chemical constitution, structure and other compounds of the object, such as resinous materials (embalming agents) and finishes, can slow down or accelerate the deterioration processes. The results showed that resinous materials have an important role for protecting linen wrappings from microbial deterioration. It also preserved the fibers’ morphological structure from deterioration caused by weathering. The FTIR results proved increasing the oxidation of the sample which not covered with resin more than the other samples as a result of its direct contact with the environmental deterioration factors.
In the third chapter, entitled "Evaluation of the influence of physicochemical changes caused by the artificial aging of linen textiles based on their susceptibility to fungal deterioration" is presented experimental study which focuses on different measurements and tests for revealing the relation between ages of the specimens and the fungal enzymatic hydrolysis of their fibers. Four groups of samples were prepared with different aging conditions. The samples of four groups were inoculated with four species of fungi that possess cellulolytic activity: Alternaria alternata, Chaetomium globosum, Aspergillus flavus and Penicillium oxalicum; and incubated for one month. The results of several previous studies showed an argument concerning the relation between the aging and fungal deterioration of textile. It was recorded that resistance of celluloses to enzymatic breakdown is a function of their degree of crystallinity. Thus, high ordered chains are so tightly packed that no water can penetrate between them, whereas the more open structure in the amorphous cellulose, allows more enzymes to interact with the cellulose chains. It was concluded that the mechanisms of fungal deterioration are exhibited in oxidation, hydrolysis, depolymerization and recrystallization processes. The influence of fungi was decreased with high aged samples. A. alternata and Chaetomium globosum showed the highest stability to enzymatic activity with the samples of all groups comparing with other species.
In the fourth chapter, entitled "Comparative study on fumigation action of essential oil, commercial fungicide and low oxygen microenvironment against museum mold, Alternaria alternata" contains a trial to make some practical modifications in the application in museums for drawing higher benefits of these control methods by reducing potential adverse effects in the future. For this purpose, ethanol (EtOH) (70% v/v), deltamethrin (commercial pesticide (CP)), essential oil (EO) from Pinus regida, and low oxygen microenvironment (LOM) were applied individually and jointly for the purpose of comparing each anti-fungal activity against museum common fungal strain Alternaria alternata. By museums safety rules, once infection happened, the antifungal methodology should be introduced into the situation to control. Although various protection measures against fungal deterioration including chemical and non-chemical approaches have been developed and taken into conservation activities, none of them would be individually effective and even some methods are currently unavailable due to crucial defects. By the current study, it is stated that the application of the chemicals (CP, EtOH. and EO) in LOM enhances its biocidal activity, causing total fungal eradication with lower concentrations than what are used in individual application of the same materials.
In the fifth chapter, entitled " The Fungicidal Effect of Ultraviolet (254 nm) Irradiation on Contaminated Museum Packing and Storing Materials" aims to investigate effectiveness of UV irradiation on sterilization of artificially infected packing and storing materials with two fungal strains as well as to estimate minimum dose of UV irradiation for its actual application on protection of museum collections. Two packing and storing materials: archival board and Japanese tissue paper, which contaminated with the spores of Penicillium commune and Chaetomium globosum, were tested. As controlling methods for fungal contamination, some specified measures are widely accepted and used in museums. Most of the previous studies related to fungal control in museums have targeted at collections themselves, while no research result aimed at disinfection of the packing and storing materials for protection of them has been found. UV light at 254 nm is one of the effectiveness control methods against fungi that induce formation of pyrimidine dimers, which alters the DNA helix and blocks microbial cell replication. The study concluded that because of the thinness and high transparency of tissue paper, UV irradiations showed higher fungicidal efficiency to its fungal contamination compared with archival board. In spite of the high resistance of C. globosum spores against UV irradiation, the rate of growth was slow, and with a little amount of perithecia or fruiting bodies and large amount of mycelium (which damaged rapidly through UV irradiation). Minimum dosage of UV irradiation with fungicidal effectiveness against all fungal contamination was estimated as 118 J/cm2.
The sixth Chapter finishes the thesis with conclusions and recommendations for future studies.
博物館における収蔵品の保存における微生物による劣化は重要な問題である。本研究ではこ
の問題に取り組み検討し､以下の結果を得た。
第１章：研究の背景を明らかにした。染織品は文化財の中で重要な位置を占める。古代エジ
プトでは亜麻が多く用いられていた。これらの文化財は微生物による劣化が指摘されている。これ
は博物館等での保存を考える上で重要である。
第２章：ミイラを包む麻布の保存効果について微生物学的視点および形態、赤外分光の視点から調べた。麻布は主に酸化を受けて変質し、繊維の結晶化度は減少する。 その結果、ミイラを包む古代エジプトの布には樹脂状物質の生成により保存環境から隔離するために微生物による影響を軽減する効果を見出した。
第３章：麻布の化学的変化が微生物による影響を実験的に調べた。検討する微生物は Alernaria alternata, Chaetomium globosum, Aspergillus flavus, Penicillium oxalicum の４種である。試験布の処理条件として ① 未処理、 ②150℃-120 時間の熱処理、 ③150℃-240 時間の熱処理、 ④150℃-240 時間の熱処理+96 時間の紫外線照射の 4 つの条件で、約１ヵ月間試験した。布の評価はセルロースの加水分解を中心に調べた。これによると、酸化、加水分解、解重合や再結晶化などが生じている。これらの変化により微生物が及ぼす影響を低減する効果が得られる。特に、A. alternata とChaetomium globosum に対する効果が著しく大きい。
第４章：低酸素環境下で、市販の殺菌剤や精油（essential oil）がカビ（Alernaria alternata）の生育に及ぼす影響について調査した。それによると、低酸素剤と化学物質(精油あるいは殺菌剤)の組み合わせが特に微生物の影響を抑制する効果が大きいことがわかった。
第５章：博物館における梱包・保存材料を汚染する微生物に対する紫外線照射（254nm)の殺菌効果について検討した。調べた梱包・保存材料は代表的な２種類のボール紙と日本産の薄葉紙である。影響はATP 法と顕微鏡を用いた形態観察により調べた。その結果、紫外線照射は効果があり、最小照射量118J/cm2 のエネルギー密度ですべての微生物を殺菌できることが判明した。薄葉紙は光の透過性が良いので殺菌効果は大きいこと、Chaetomium globosum は紫外線に対する抵抗性が高いこともわかった。
以上の検討から、博物館所蔵されるミイラを包む麻布を侵襲する微生物に対し、その生物活性の抑制方法を実用的な視点から明らかにできた。これらは博物館での資料保存活動に生かすことができると考えられた。
The first chapter of the thesis is "Introduction". Textiles are an important source of reference for the cultural studies since they represent a significant aspect of craft manifestation directly correlated to people’s culture. The majority of ancient Egyptian textiles are of linen which was made from flax. Contamination of textile objects presented in exhibition rooms or stored in depots and their spoilage by fungi is nowadays a significant problem for cultural heritage conservator. The beneficial measures to avoid fungal contamination in cultural institutions are strongly required. The individual use of each control method in museums cannot fittingly eradicate such problem. Thus, some modifications of the treatment techniques is required for gaining suitable way for controlling fungal contamination in museums.
The second chapter of the thesis, "Microbiological, morphological and spectroscopic study on the effect of resinous materials in the preservation of wrapping textiles of mummies" includes the isolation of several fungal strains from ancient linen textile samples of mummies wrappings; evaluation the fungal deterioration of ancient samples; and evaluation the role of one of ancient Egyptian additives materials (resinous materials) on protection of the wrapping textile from environmental factors (especially microorganisms). The tested ancient samples were characterized depending on the resinous materials adherent with their fibers. The previous studies stated that the chemical constitution, structure and other compounds of the object, such as resinous materials (embalming agents) and finishes, can slow down or accelerate the deterioration processes. The results showed that resinous materials have an important role for protecting linen wrappings from microbial deterioration. It also preserved the fibers’ morphological structure from deterioration caused by weathering. The FTIR results proved increasing the oxidation of the sample which not covered with resin more than the other samples as a result of its direct contact with the environmental deterioration factors.
In the third chapter, entitled "Evaluation of the influence of physicochemical changes caused by the artificial aging of linen textiles based on their susceptibility to fungal deterioration" is presented experimental study which focuses on different measurements and tests for revealing the relation between ages of the specimens and the fungal enzymatic hydrolysis of their fibers. Four groups of samples were prepared with different aging conditions. The samples of four groups were inoculated with four species of fungi that possess cellulolytic activity: Alternaria alternata, Chaetomium globosum, Aspergillus flavus and Penicillium oxalicum; and incubated for one month. The results of several previous studies showed an argument concerning the relation between the aging and fungal deterioration of textile. It was recorded that resistance of celluloses to enzymatic breakdown is a function of their degree of crystallinity. Thus, high ordered chains are so tightly packed that no water can penetrate between them, whereas the more open structure in the amorphous cellulose, allows more enzymes to interact with the cellulose chains. It was concluded that the mechanisms of fungal deterioration are exhibited in oxidation, hydrolysis, depolymerization and recrystallization processes. The influence of fungi was decreased with high aged samples. A. alternata and Chaetomium globosum showed the highest stability to enzymatic activity with the samples of all groups comparing with other species.
In the fourth chapter, entitled "Comparative study on fumigation action of essential oil, commercial fungicide and low oxygen microenvironment against museum mold, Alternaria alternata" contains a trial to make some practical modifications in the application in museums for drawing higher benefits of these control methods by reducing potential adverse effects in the future. For this purpose, ethanol (EtOH) (70% v/v), deltamethrin (commercial pesticide (CP)), essential oil (EO) from Pinus regida, and low oxygen microenvironment (LOM) were applied individually and jointly for the purpose of comparing each anti-fungal activity against museum common fungal strain Alternaria alternata. By museums safety rules, once infection happened, the antifungal methodology should be introduced into the situation to control. Although various protection measures against fungal deterioration including chemical and non-chemical approaches have been developed and taken into conservation activities, none of them would be individually effective and even some methods are currently unavailable due to crucial defects. By the current study, it is stated that the application of the chemicals (CP, EtOH. and EO) in LOM enhances its biocidal activity, causing total fungal eradication with lower concentrations than what are used in individual application of the same materials.
In the fifth chapter, entitled " The Fungicidal Effect of Ultraviolet (254 nm) Irradiation on Contaminated Museum Packing and Storing Materials" aims to investigate effectiveness of UV irradiation on sterilization of artificially infected packing and storing materials with two fungal strains as well as to estimate minimum dose of UV irradiation for its actual application on protection of museum collections. Two packing and storing materials: archival board and Japanese tissue paper, which contaminated with the spores of Penicillium commune and Chaetomium globosum, were tested. As controlling methods for fungal contamination, some specified measures are widely accepted and used in museums. Most of the previous studies related to fungal control in museums have targeted at collections themselves, while no research result aimed at disinfection of the packing and storing materials for protection of them has been found. UV light at 254 nm is one of the effectiveness control methods against fungi that induce formation of pyrimidine dimers, which alters the DNA helix and blocks microbial cell replication. The study concluded that because of the thinness and high transparency of tissue paper, UV irradiations showed higher fungicidal efficiency to its fungal contamination compared with archival board. In spite of the high resistance of C. globosum spores against UV irradiation, the rate of growth was slow, and with a little amount of perithecia or fruiting bodies and large amount of mycelium (which damaged rapidly through UV irradiation). Minimum dosage of UV irradiation with fungicidal effectiveness against all fungal contamination was estimated as 118 J/cm2.
The sixth Chapter finishes the thesis with conclusions and recommendations for future studies.
博物館における収蔵品の保存における微生物による劣化は重要な問題である。本研究ではこ
の問題に取り組み検討し､以下の結果を得た。
第１章：研究の背景を明らかにした。染織品は文化財の中で重要な位置を占める。古代エジ
プトでは亜麻が多く用いられていた。これらの文化財は微生物による劣化が指摘されている。これ
は博物館等での保存を考える上で重要である。
第２章：ミイラを包む麻布の保存効果について微生物学的視点および形態、赤外分光の視点から調べた。麻布は主に酸化を受けて変質し、繊維の結晶化度は減少する。 その結果、ミイラを包む古代エジプトの布には樹脂状物質の生成により保存環境から隔離するために微生物による影響を軽減する効果を見出した。
第３章：麻布の化学的変化が微生物による影響を実験的に調べた。検討する微生物は Alernaria alternata, Chaetomium globosum, Aspergillus flavus, Penicillium oxalicum の４種である。試験布の処理条件として ① 未処理、 ②150℃-120 時間の熱処理、 ③150℃-240 時間の熱処理、 ④150℃-240 時間の熱処理+96 時間の紫外線照射の 4 つの条件で、約１ヵ月間試験した。布の評価はセルロースの加水分解を中心に調べた。これによると、酸化、加水分解、解重合や再結晶化などが生じている。これらの変化により微生物が及ぼす影響を低減する効果が得られる。特に、A. alternata とChaetomium globosum に対する効果が著しく大きい。
第４章：低酸素環境下で、市販の殺菌剤や精油（essential oil）がカビ（Alernaria alternata）の生育に及ぼす影響について調査した。それによると、低酸素剤と化学物質(精油あるいは殺菌剤)の組み合わせが特に微生物の影響を抑制する効果が大きいことがわかった。
第５章：博物館における梱包・保存材料を汚染する微生物に対する紫外線照射（254nm)の殺菌効果について検討した。調べた梱包・保存材料は代表的な２種類のボール紙と日本産の薄葉紙である。影響はATP 法と顕微鏡を用いた形態観察により調べた。その結果、紫外線照射は効果があり、最小照射量118J/cm2 のエネルギー密度ですべての微生物を殺菌できることが判明した。薄葉紙は光の透過性が良いので殺菌効果は大きいこと、Chaetomium globosum は紫外線に対する抵抗性が高いこともわかった。
以上の検討から、博物館所蔵されるミイラを包む麻布を侵襲する微生物に対し、その生物活性の抑制方法を実用的な視点から明らかにできた。これらは博物館での資料保存活動に生かすことができると考えられた。