Moulds have been reported to destroy volumes of timbers in buildings annually. As a result, timber components within the built environment decline and fail to fulfill their basic requirements. This research focused on...Moulds have been reported to destroy volumes of timbers in buildings annually. As a result, timber components within the built environment decline and fail to fulfill their basic requirements. This research focused on the isolation and evaluation of the prevalence and effects of deteriorating moulds in the rain forest and swampy rain forest regions of Nigeria where the water activity is as high as 0.7. To accomplish this, decayed timber samples were aseptically collected on buildings from six strategic locations. The samples were serially diluted and inoculated onto Sabouraud Dextrose Agar medium in Petal dishes. The Petri dishes were incubated for 72 h at 30 ~C. Thereafter, moulds were isolated through visual and microscopic observations. The commonly encountered moulds were evaluated and analyzed. It was observed that, prevalence of moulds on buildings used for non residential purpose were higher. There was no significant difference between the prevalence on the components located inside the building and those outside the building. Ceiba pentandra exhibited highest degradation while Masonia altissima resisted most. The most deteriorating moulds were Aspergillus, Mucor, Rhizopus and Gliocladium. The deteriorations of Ceiba pentandra, Afzelia africana, Lophira alata, Anogessus leocarpus and Gossweilerodendron balsamiferum timbers under Aspergillus attack were projected.展开更多
Wood can be a suitable alternative to energy-intensive materials in various applications.Nev-ertheless,its susceptibility to weathering and decay has significantly hindered the broad adop-tion of the most commercially...Wood can be a suitable alternative to energy-intensive materials in various applications.Nev-ertheless,its susceptibility to weathering and decay has significantly hindered the broad adop-tion of the most commercially significant wood species.While current solutions do tackle certain challenges,they often come with disadvantages like high costs,environmental risks,and/or in-efficiencies.Nanotechnology-based methods can be employed to mitigate these weaknesses and create durable,sustainable wood materials.In this review,we delve into cutting-edge advance-ments in the development of biodeterioration-resistant wood through innovative nanotechnol-ogy approaches.These methods usually involve the application of nanomaterials,either pos-sessing biocidal properties or serving as carriers for biocides.We systematically describe these approaches and compare them to conventional wood modification methods.Additionally,this re-view provides a brief overview of the prevalent biodeteriorating organisms and their mechanisms of action,which notably impact the development and choice of a suitable strategy for wood mod-ification/treatment.Given the requirements of biodeteriorating organisms for growth and wood degradation,it is expected that the new nanotechnology-based approaches to enhance wood dura-bility may provide innovative broad-spectrum biocidal nanosystems.These systems can simulta-neously induce alterations in the physicochemical properties of wood,thereby constraining the availability of the growth requirements.These alterations can efficiently inhibit the biodeterio-ration process by decreasing water absorption,restricting access to the wood components,and reducing void spaces within the wood structure.Finally,this review highlights the new oppor-tunities,challenges,and perspectives of nanotechnology methods for biodeterioration-resistant wood,through which some techno-economic,environmental and safety aspects associated with these methods are addressed.展开更多
UV-C irradiation critically effects the growth of micro-fungi and also deteriorate leather materials. In the present study vegetable tanned and chrome tanned leather were infected with pure cultures of Aspergillus nig...UV-C irradiation critically effects the growth of micro-fungi and also deteriorate leather materials. In the present study vegetable tanned and chrome tanned leather were infected with pure cultures of Aspergillus niger and Aspergillus flavus, which were isolated from stored leather materials. UV-C light (λ = 254 nm) was applied on infected leather for 15 and 60 min. The changes in leather qualities were examined through weight, tensile strength, scanning electron microscope, energy dispersive X-ray and Fourier transform infrared spectroscopy study after 15 and 30 days of fungal inoculation. Vegetable tanned leather was more vulnerable in case of fungal attack than chrome tanned leather while A. flavus showed more influence on leather deterioration than A. niger. The results showed that weight loss after 30 days for 15 and 60 min irradiation exposure was 1.3% compared to A. flavus infected leather (3.93%). The tensile strength of vegetable and chrome tanned UV irradiated leather was increased by 44% and 7% respectively. The scanning electron microscopic images exhibit the limited presence of conidiophores in UV-C exposed leather which confirmed the potentiality of irradiation for controlling fungal growth. The infrared spectral analysis of UV-C exposed infected leather samples showed neither shifting of wavenumber nor displacement of any functional groups. Alto-gether the efficacy of UV-C irradiation against biodeterioration of leather was concluded to be effective. This method can be used to control fungal growth without compromising the leather quality.展开更多
UV-C irradiation critically effects the growth of micro-fungi and also deteriorate leather materials.In the present study vegetable tanned and chrome tanned leather were infected with pure cultures of Aspergillus nige...UV-C irradiation critically effects the growth of micro-fungi and also deteriorate leather materials.In the present study vegetable tanned and chrome tanned leather were infected with pure cultures of Aspergillus niger and Aspergillus flavus,which were isolated from stored leather materials.UV-C light(λ=254 nm)was applied on infected leather for 15 and 60 min.The changes in leather qualities were examined through weight,tensile strength,scanning electron microscope,energy dispersive X-ray and Fourier transform infrared spectroscopy study after 15 and 30 days of fungal inoculation.Vegetable tanned leather was more vulnerable in case of fungal attack than chrome tanned leather while A.flavus showed more influence on leather deterioration than A.niger.The results showed that weight loss after 30 days for 15 and 60 min irradiation exposure was 1.3%compared to A.flavus infected leather(3.93%).The tensile strength of vegetable and chrome tanned UV irradiated leather was increased by 44%and 7%respectively.The scanning electron microscopic images exhibit the limited presence of conidiophores in UV-C exposed leather which confirmed the potentiality of irradiation for controlling fungal growth.The infrared spectral analysis of UV-C exposed infected leather samples showed neither shifting of wavenumber nor displacement of any functional groups.Alto-gether the efficacy of UV-C irradiation against biodeterioration of leather was concluded to be effective.This method can be used to control fungal growth without compromising the leather quality.展开更多
Over the last decade,the oriented strand board(OSB)market presented meaningful growth.However,as a woodbased product,because of its anatomical structure and chemical composition,OSB can be damaged by biodeterioration ...Over the last decade,the oriented strand board(OSB)market presented meaningful growth.However,as a woodbased product,because of its anatomical structure and chemical composition,OSB can be damaged by biodeterioration agents.Given that,the biodeterioration of OSB panels must be investigated to improve its durability.In this way,this work analyses the biological resistance against termites(Cryptotermes brevis and Nasutitermes corniger)of heat-treated OSB panels made with Eucalyptus wood glued with vegetable-based polyurethane-an ecofriendly and sustainable adhesive derived from castor oil.Various panels were produced with different layers compositions(face:core:face of 25:50:25 and 30:40:30)in wood mass proportion and were submitted to postproduction heat treatment(at 175℃ and 200℃)replacing the use of chemical insecticides.The influence of the layers variation and heat treatment temperature were evaluated,and these results were compared with commercial panels(made from pinus wood with insecticide).The results showed that the heat treatment did not improve the resistance against termite attack.However,all the experimental panels presented a satisfactory performance that was compatible with the commercial panels produced with insecticide available in the Brazilian market.The combination of Eucalyptus wood and castor oil adhesive to produce OSB,in any variation of layer composition,demonstrated natural resistance against termite attack compatible with the commercial panels,even without using chemical additives to increase durability.展开更多
High concentrations of environmental fungi in the archives repositories are dangerous for the documents preserved in those places and for the workers'health.The aims of this work were to evaluate the behavior of t...High concentrations of environmental fungi in the archives repositories are dangerous for the documents preserved in those places and for the workers'health.The aims of this work were to evaluate the behavior of the fungal concentration and diversity in the indoor air of repositories of 3 archives located in Havana,Cuba,and to demonstrate the potential risk that these taxa represent for the documentary heritage preserved in these institutions.The indoor and outdoor environments were sampled with a biocollector.From the I/O ratios,it was evident that two of the studied archives were not contaminated,while one of them did show contamination despite having temperature and relative humidity values very similar to the other two.Aspergillus,Penicillium and Cladosporium were the predominant genera in the indoor environments.New finds for archival environments were the genera Harposporium and Scolecobasidium.The principal species classified ecologically as abundant were C.cladosporioides and P.citrinum.They are known as opportunistic pathogenic fungi.All the analyzed taxa excreted acids,the most of them degraded cellulose,starch and gelatin while about 48%excreted different pigments.But 33%of them showed the highest biodeteriogenic potential,evidencing that they are the most dangerous for the documentary collections.展开更多
The science and technology interact with the art in several ways. Biotechnological coupled with analytical approaches can play an important role in protecting and preserving cultural heritage for future generations. M...The science and technology interact with the art in several ways. Biotechnological coupled with analytical approaches can play an important role in protecting and preserving cultural heritage for future generations. Many microorganisms influenced by environmental conditions are the main responsible for biological contamination in built heritage. Biocides based on chemical compounds have been used to mitigate this problem. Thus, it is vitally important to develop proper remediation actions based on environmentally innocuous alternative. Bacillus specie is emerging as an optimistic alternative for built heritage treatment due to their capacity to produce secondary metabolites with antagonistic activities against many fungal pathogens. Therefore, the intent of this work was to access a rapid evaluation of antifungal potential of bioactive metabolites produced by Bacillus strains and simultaneously their characterization using spectroscopic (NMR) and chromatographic techniques (LC-ESI-MS). The high antifungal activity obtained for Bacillus sp. active compounds produced in this study confirms the great potential to suppress biodeteriogenic fungi growth on historical artworks. Additionally, the proposed methodology allowed to access bioactive metabolites produced without need of the laborious total previous isolation and could be used as a viable alternative to be employed for screening and production of new green biocides.展开更多
The effect of biodeteriogenic living organisms on historical and archeological sites is a well-known problem affecting the world’s cultural heritage. Indeed, the growth inside the bricks of shrubs and herbs roots can...The effect of biodeteriogenic living organisms on historical and archeological sites is a well-known problem affecting the world’s cultural heritage. Indeed, the growth inside the bricks of shrubs and herbs roots can cause breakage, collapse and, detachment of materials. The knowledge of the spontaneous vascular flora present on monuments is essential for protection and safeguarding of cultural heritage. In this paper, we identify and describe biodeteriogenic vascular flora of three historical Calabrian (Southern Italy) churches, showing the relationship between plant biodiversity and exposure and building material of churches. The species present on the wall and in perimeter for each church were sampled noting substrate type, surface inclination (vertical or horizontal) and exposure. The total number of plant species recorded was 27. Hemicryptophytes (41%) prevail over the other biological forms and the most represented families are that of the Asteraceae. Parietaria judaica is the only species present in all three sites. Substrate type, climatic condition and surface inclination affect the floristic composition. Sixteen out of 27 species grow on vertical surfaces, all Geophythes and Chamaephytes grow on horizontal surfaces, while Therophytes were rather on vertical surfaces. A significant difference was found in the Hazard Index values in the three churches. Only one site, presents a high average value of Hazard Index, due to the simultaneous presence of Ailanthus altissima, Ficus carica, Rubus ulmifolius and Sambucus nigra. The data collected indicate that the flora growing on wall of three Calabrian churches partially reflects the floristic context in which they are located. The diversity of the vegetational spectrum is remarkable, most of the plants are ruderal herbaceous, many weeds and invasive, and for the most part typical of the Mediterranean environment. The data collected contribute to the knowledge of the spontaneous vascular flora present on three historical Calabrian churches and their biodiversity, also in terms of conservation interest, considering its biodeteriogenic potential in the evaluation of the impact of the vegetation on each monument.展开更多
The present study aims to evaluate the environmental effect on fungal community composition associated with biodeterioration occurring in stones （soapstone） at two distinct locations in Minas Gerais State, Brazil： ...The present study aims to evaluate the environmental effect on fungal community composition associated with biodeterioration occurring in stones （soapstone） at two distinct locations in Minas Gerais State, Brazil： Congonhas city and Sanctuary of Cara^a. Four collections of fungal communities over one year were obtained from both research sites from the soapstone block surfaces exposed for over two decades. The molecular diversity profile of the fungal community at the two localities was obtained by DGGE （Denaturing Gradient Gel Electrophoresis）, and the genomes of the most representative population were sequenced. DGGE showed the formation of two clusters with filamentous fungal communities. Sequencing of the most representative bands revealed the presence of fungi associated with the biodeterioration of soapstone. In addition, many of the identified species were associated with photobionts that could generate lichens, indicating that environmental characteristics affect the occurrence of filamentous fungi, which leads to biodeterioration of stones. Authors＇ study focused on an environmental variation of an extreme habitat for fungi associated with soapstone in the state of Minas Gerais, Brazil and identified the presence of interesting rock-inhabiting fungal communities including species related to lichens, which can accelerate the deterioration of stones by the production of organic acids.展开更多
Biocorrosion, as well as the biodeterioration of crude oil and its derivatives, is one of the major environmental, operational and economic problems in the Venezuelan oil industry. Fungal contaminants are able to prod...Biocorrosion, as well as the biodeterioration of crude oil and its derivatives, is one of the major environmental, operational and economic problems in the Venezuelan oil industry. Fungal contaminants are able to produce large quantities of biomass and synthesize peroxides and organic acids, causing severe damage on metal surfaces and promoting the contamination and biodeterioration of fuels. No evidences regarding fungal strains have been reported to be associated to petroleum naphtha, widely used as a diluent of extra heavy crude oil (EHCO) in the exploitation processes of the Orinoco Oil Belt, the biggest proven reserve of EHCO worldwide. The aims of this paper were to isolate and identify fungal strains from the naphtha storage tank and the naphtha distribution network from an oil field operator in Venezuela. The results showed the isolation of four different fungal strains. The molecular identification by 28S rRNA sequencing and phylogenetic tree analysis allowed us to identify the presence of: 1) a new uncultured Ascomycota fungus species BM-103, with high identity to novel hyphomycetes Noosia banksiae and Sporidesmium tengii, in the naphtha storage tank;2) two yeasts, Rhodotorula mucilaginosa BM-104 (Phylum Basidiomycota) and Wickerhamia sp. BM-105 (Phylum Ascomycota), in a highly damaged naphtha pipeline branch and;3) Cladosporium cladosporioides BM-102 (Phylum Ascomycota) in a cluster oil well. DNA fingerprinting analysis using ERIC-PCR primers pairs also allowed us to detect the presence of R. mucilaginosa BM-104 right in the access of the studied naphtha system. Interestingly, R. mucilaginosa and C. cladosporioides were previously reported as predominant fungal contaminants of diesel and jet fuel and of kerosene and fuel storage systems, respectively. This paper represents the first evidence of fungal strains isolated and identified from the naphtha systems in the Venezuelan oil industry. The results obtained are discussed.展开更多
The start and the course of bio-corrosion are conditioned by many factors which include biological effects like the influence of vegetation and microorganisms causing the deterioration of materials. The influence of b...The start and the course of bio-corrosion are conditioned by many factors which include biological effects like the influence of vegetation and microorganisms causing the deterioration of materials. The influence of bacteria causing the deterioration of concrete has been linked to the generation of biogenic sulphuric and nitric acids which originate in corrosion process by dissolution of calcium containing minerals from the concrete matrices. This paper primarily focuses on the investigation of influence of sulphur-oxidising bacteria Acidithiobacillus thiooxidans and sulphate-reducing bacteria Desulfovibrio desulfuricans at the resistance degree of cement composites. Various concrete composites with 5% addition of black coal fly ash as cement replacement as well as the reference samples without coal fly ash addition were studied in the experiments environments of sewage system proceeded during 90 days. The The laboratory experiments as well as experiments in situ in real corrosion was manifested by surface changes and weight changes of cement composites samples as well as changes in pH values of leachates. Considerable surface changes were detected in all investigated samples by microscopic methods. Crystals precipitated on concrete samples surface were identified by EDX as mixture of gypsum and ettringite. The roughness increases of surface of cement microscopy. composites were determined by confocal laser scanning展开更多
The Buyeo Royal Tomb No. 1 is an ancient tomb built in the late 6<sup>th</sup> and early 7<sup>th</sup> century. The four walls of the main room have murals of four guardian deities, and the ce...The Buyeo Royal Tomb No. 1 is an ancient tomb built in the late 6<sup>th</sup> and early 7<sup>th</sup> century. The four walls of the main room have murals of four guardian deities, and the ceiling has murals of lotus and cloud patterns. This study assessed the optimal growth conditions of two fungal (Fusarium oxysporum, Mortierella sp.) and four bacterial (Bacillus cereus, Cupriavidus campinensis, Streptomyces avidinii, Streptomyces cirratus) strains isolated from the Tomb No. 1, along with their effects on the painting layer. The two fungi showed optimal growth at 20°C - 30°C under both nutrient and non-nutrient conditions. These strains did not decompose or discolor the three pigments (cinnabar, hematite, oyster shell white);however, M. sp. showed slight decomposition of the media (starch paste, sea weed). The four bacterial strains showed the most active growth at 20°C - 25°C under nutrient conditions and did not grow under non-nutrient conditions. These bacteria commonly degraded animal glue and sea weed components. In addition, S. cirratus degraded starch. The genus Streptomyces discolored the pigment medium to brown and black, suggesting a possible risk of discoloration of the murals. The current environment in Tomb No. 1 was sufficient for microorganism growth, and the presence of strains such as soil bacteria and actinomycetes on the mural surface may damage the murals. The findings of this study could be helpful for preserving mural tombs against biological damage caused by microorganisms that are already present or may be present in the tombs in the future. These findings also provide guidelines for comprehensive conservation management.展开更多
文摘Moulds have been reported to destroy volumes of timbers in buildings annually. As a result, timber components within the built environment decline and fail to fulfill their basic requirements. This research focused on the isolation and evaluation of the prevalence and effects of deteriorating moulds in the rain forest and swampy rain forest regions of Nigeria where the water activity is as high as 0.7. To accomplish this, decayed timber samples were aseptically collected on buildings from six strategic locations. The samples were serially diluted and inoculated onto Sabouraud Dextrose Agar medium in Petal dishes. The Petri dishes were incubated for 72 h at 30 ~C. Thereafter, moulds were isolated through visual and microscopic observations. The commonly encountered moulds were evaluated and analyzed. It was observed that, prevalence of moulds on buildings used for non residential purpose were higher. There was no significant difference between the prevalence on the components located inside the building and those outside the building. Ceiba pentandra exhibited highest degradation while Masonia altissima resisted most. The most deteriorating moulds were Aspergillus, Mucor, Rhizopus and Gliocladium. The deteriorations of Ceiba pentandra, Afzelia africana, Lophira alata, Anogessus leocarpus and Gossweilerodendron balsamiferum timbers under Aspergillus attack were projected.
文摘Wood can be a suitable alternative to energy-intensive materials in various applications.Nev-ertheless,its susceptibility to weathering and decay has significantly hindered the broad adop-tion of the most commercially significant wood species.While current solutions do tackle certain challenges,they often come with disadvantages like high costs,environmental risks,and/or in-efficiencies.Nanotechnology-based methods can be employed to mitigate these weaknesses and create durable,sustainable wood materials.In this review,we delve into cutting-edge advance-ments in the development of biodeterioration-resistant wood through innovative nanotechnol-ogy approaches.These methods usually involve the application of nanomaterials,either pos-sessing biocidal properties or serving as carriers for biocides.We systematically describe these approaches and compare them to conventional wood modification methods.Additionally,this re-view provides a brief overview of the prevalent biodeteriorating organisms and their mechanisms of action,which notably impact the development and choice of a suitable strategy for wood mod-ification/treatment.Given the requirements of biodeteriorating organisms for growth and wood degradation,it is expected that the new nanotechnology-based approaches to enhance wood dura-bility may provide innovative broad-spectrum biocidal nanosystems.These systems can simulta-neously induce alterations in the physicochemical properties of wood,thereby constraining the availability of the growth requirements.These alterations can efficiently inhibit the biodeterio-ration process by decreasing water absorption,restricting access to the wood components,and reducing void spaces within the wood structure.Finally,this review highlights the new oppor-tunities,challenges,and perspectives of nanotechnology methods for biodeterioration-resistant wood,through which some techno-economic,environmental and safety aspects associated with these methods are addressed.
基金RUSA 2.0(Rashtriya Uchchattar Shiksha Abhiyan)scheme availed by the Government of India.Also,this work was performed under the collaborative research scheme no(UGC-DAE-CSR-KC/CRS/19/RB-06/1049)of University Grants Commission Department of Atomic Energy Consortium for Scientific Research Kolkata Centre.
文摘UV-C irradiation critically effects the growth of micro-fungi and also deteriorate leather materials. In the present study vegetable tanned and chrome tanned leather were infected with pure cultures of Aspergillus niger and Aspergillus flavus, which were isolated from stored leather materials. UV-C light (λ = 254 nm) was applied on infected leather for 15 and 60 min. The changes in leather qualities were examined through weight, tensile strength, scanning electron microscope, energy dispersive X-ray and Fourier transform infrared spectroscopy study after 15 and 30 days of fungal inoculation. Vegetable tanned leather was more vulnerable in case of fungal attack than chrome tanned leather while A. flavus showed more influence on leather deterioration than A. niger. The results showed that weight loss after 30 days for 15 and 60 min irradiation exposure was 1.3% compared to A. flavus infected leather (3.93%). The tensile strength of vegetable and chrome tanned UV irradiated leather was increased by 44% and 7% respectively. The scanning electron microscopic images exhibit the limited presence of conidiophores in UV-C exposed leather which confirmed the potentiality of irradiation for controlling fungal growth. The infrared spectral analysis of UV-C exposed infected leather samples showed neither shifting of wavenumber nor displacement of any functional groups. Alto-gether the efficacy of UV-C irradiation against biodeterioration of leather was concluded to be effective. This method can be used to control fungal growth without compromising the leather quality.
基金supported by RUSA 2.0(Rashtriya Uchchattar Shiksha Abhiyan)scheme avaited by the Government of Indiathe collaborative research scheme no(JGC-DAE-CSR-KC/CRS/19/RB-06/1049)of University Grants Commission Department of Atomic Energy Consortium for Scientifhc Research Kolkata Centre.
文摘UV-C irradiation critically effects the growth of micro-fungi and also deteriorate leather materials.In the present study vegetable tanned and chrome tanned leather were infected with pure cultures of Aspergillus niger and Aspergillus flavus,which were isolated from stored leather materials.UV-C light(λ=254 nm)was applied on infected leather for 15 and 60 min.The changes in leather qualities were examined through weight,tensile strength,scanning electron microscope,energy dispersive X-ray and Fourier transform infrared spectroscopy study after 15 and 30 days of fungal inoculation.Vegetable tanned leather was more vulnerable in case of fungal attack than chrome tanned leather while A.flavus showed more influence on leather deterioration than A.niger.The results showed that weight loss after 30 days for 15 and 60 min irradiation exposure was 1.3%compared to A.flavus infected leather(3.93%).The tensile strength of vegetable and chrome tanned UV irradiated leather was increased by 44%and 7%respectively.The scanning electron microscopic images exhibit the limited presence of conidiophores in UV-C exposed leather which confirmed the potentiality of irradiation for controlling fungal growth.The infrared spectral analysis of UV-C exposed infected leather samples showed neither shifting of wavenumber nor displacement of any functional groups.Alto-gether the efficacy of UV-C irradiation against biodeterioration of leather was concluded to be effective.This method can be used to control fungal growth without compromising the leather quality.
基金financed by Coordination for the Improvement of Higher Education Personnel,Brazil(CAPES,https://www.gov.br/capes/pt-br)(accessed on 22 September 2024)Finance Code 001(ESS,FDM)+1 种基金Sao Paulo State Research Support Foundation(FAPESP,https://fapesp.br/)(accessed on 22 September 2024)(CIC,grant number 2015/04660-0)National Council for Scientific and Technological Development(CNPq,https://www.gov.br/cnpq/pt-br)(accessed on 22 September 2024)(grant numbers 308937/2021-0(CIC),306576/2020-1(ECB),and 303099/2022-4(JBP)).
文摘Over the last decade,the oriented strand board(OSB)market presented meaningful growth.However,as a woodbased product,because of its anatomical structure and chemical composition,OSB can be damaged by biodeterioration agents.Given that,the biodeterioration of OSB panels must be investigated to improve its durability.In this way,this work analyses the biological resistance against termites(Cryptotermes brevis and Nasutitermes corniger)of heat-treated OSB panels made with Eucalyptus wood glued with vegetable-based polyurethane-an ecofriendly and sustainable adhesive derived from castor oil.Various panels were produced with different layers compositions(face:core:face of 25:50:25 and 30:40:30)in wood mass proportion and were submitted to postproduction heat treatment(at 175℃ and 200℃)replacing the use of chemical insecticides.The influence of the layers variation and heat treatment temperature were evaluated,and these results were compared with commercial panels(made from pinus wood with insecticide).The results showed that the heat treatment did not improve the resistance against termite attack.However,all the experimental panels presented a satisfactory performance that was compatible with the commercial panels produced with insecticide available in the Brazilian market.The combination of Eucalyptus wood and castor oil adhesive to produce OSB,in any variation of layer composition,demonstrated natural resistance against termite attack compatible with the commercial panels,even without using chemical additives to increase durability.
文摘High concentrations of environmental fungi in the archives repositories are dangerous for the documents preserved in those places and for the workers'health.The aims of this work were to evaluate the behavior of the fungal concentration and diversity in the indoor air of repositories of 3 archives located in Havana,Cuba,and to demonstrate the potential risk that these taxa represent for the documentary heritage preserved in these institutions.The indoor and outdoor environments were sampled with a biocollector.From the I/O ratios,it was evident that two of the studied archives were not contaminated,while one of them did show contamination despite having temperature and relative humidity values very similar to the other two.Aspergillus,Penicillium and Cladosporium were the predominant genera in the indoor environments.New finds for archival environments were the genera Harposporium and Scolecobasidium.The principal species classified ecologically as abundant were C.cladosporioides and P.citrinum.They are known as opportunistic pathogenic fungi.All the analyzed taxa excreted acids,the most of them degraded cellulose,starch and gelatin while about 48%excreted different pigments.But 33%of them showed the highest biodeteriogenic potential,evidencing that they are the most dangerous for the documentary collections.
文摘The science and technology interact with the art in several ways. Biotechnological coupled with analytical approaches can play an important role in protecting and preserving cultural heritage for future generations. Many microorganisms influenced by environmental conditions are the main responsible for biological contamination in built heritage. Biocides based on chemical compounds have been used to mitigate this problem. Thus, it is vitally important to develop proper remediation actions based on environmentally innocuous alternative. Bacillus specie is emerging as an optimistic alternative for built heritage treatment due to their capacity to produce secondary metabolites with antagonistic activities against many fungal pathogens. Therefore, the intent of this work was to access a rapid evaluation of antifungal potential of bioactive metabolites produced by Bacillus strains and simultaneously their characterization using spectroscopic (NMR) and chromatographic techniques (LC-ESI-MS). The high antifungal activity obtained for Bacillus sp. active compounds produced in this study confirms the great potential to suppress biodeteriogenic fungi growth on historical artworks. Additionally, the proposed methodology allowed to access bioactive metabolites produced without need of the laborious total previous isolation and could be used as a viable alternative to be employed for screening and production of new green biocides.
文摘The effect of biodeteriogenic living organisms on historical and archeological sites is a well-known problem affecting the world’s cultural heritage. Indeed, the growth inside the bricks of shrubs and herbs roots can cause breakage, collapse and, detachment of materials. The knowledge of the spontaneous vascular flora present on monuments is essential for protection and safeguarding of cultural heritage. In this paper, we identify and describe biodeteriogenic vascular flora of three historical Calabrian (Southern Italy) churches, showing the relationship between plant biodiversity and exposure and building material of churches. The species present on the wall and in perimeter for each church were sampled noting substrate type, surface inclination (vertical or horizontal) and exposure. The total number of plant species recorded was 27. Hemicryptophytes (41%) prevail over the other biological forms and the most represented families are that of the Asteraceae. Parietaria judaica is the only species present in all three sites. Substrate type, climatic condition and surface inclination affect the floristic composition. Sixteen out of 27 species grow on vertical surfaces, all Geophythes and Chamaephytes grow on horizontal surfaces, while Therophytes were rather on vertical surfaces. A significant difference was found in the Hazard Index values in the three churches. Only one site, presents a high average value of Hazard Index, due to the simultaneous presence of Ailanthus altissima, Ficus carica, Rubus ulmifolius and Sambucus nigra. The data collected indicate that the flora growing on wall of three Calabrian churches partially reflects the floristic context in which they are located. The diversity of the vegetational spectrum is remarkable, most of the plants are ruderal herbaceous, many weeds and invasive, and for the most part typical of the Mediterranean environment. The data collected contribute to the knowledge of the spontaneous vascular flora present on three historical Calabrian churches and their biodiversity, also in terms of conservation interest, considering its biodeteriogenic potential in the evaluation of the impact of the vegetation on each monument.
文摘The present study aims to evaluate the environmental effect on fungal community composition associated with biodeterioration occurring in stones （soapstone） at two distinct locations in Minas Gerais State, Brazil： Congonhas city and Sanctuary of Cara^a. Four collections of fungal communities over one year were obtained from both research sites from the soapstone block surfaces exposed for over two decades. The molecular diversity profile of the fungal community at the two localities was obtained by DGGE （Denaturing Gradient Gel Electrophoresis）, and the genomes of the most representative population were sequenced. DGGE showed the formation of two clusters with filamentous fungal communities. Sequencing of the most representative bands revealed the presence of fungi associated with the biodeterioration of soapstone. In addition, many of the identified species were associated with photobionts that could generate lichens, indicating that environmental characteristics affect the occurrence of filamentous fungi, which leads to biodeterioration of stones. Authors＇ study focused on an environmental variation of an extreme habitat for fungi associated with soapstone in the state of Minas Gerais, Brazil and identified the presence of interesting rock-inhabiting fungal communities including species related to lichens, which can accelerate the deterioration of stones by the production of organic acids.
文摘Biocorrosion, as well as the biodeterioration of crude oil and its derivatives, is one of the major environmental, operational and economic problems in the Venezuelan oil industry. Fungal contaminants are able to produce large quantities of biomass and synthesize peroxides and organic acids, causing severe damage on metal surfaces and promoting the contamination and biodeterioration of fuels. No evidences regarding fungal strains have been reported to be associated to petroleum naphtha, widely used as a diluent of extra heavy crude oil (EHCO) in the exploitation processes of the Orinoco Oil Belt, the biggest proven reserve of EHCO worldwide. The aims of this paper were to isolate and identify fungal strains from the naphtha storage tank and the naphtha distribution network from an oil field operator in Venezuela. The results showed the isolation of four different fungal strains. The molecular identification by 28S rRNA sequencing and phylogenetic tree analysis allowed us to identify the presence of: 1) a new uncultured Ascomycota fungus species BM-103, with high identity to novel hyphomycetes Noosia banksiae and Sporidesmium tengii, in the naphtha storage tank;2) two yeasts, Rhodotorula mucilaginosa BM-104 (Phylum Basidiomycota) and Wickerhamia sp. BM-105 (Phylum Ascomycota), in a highly damaged naphtha pipeline branch and;3) Cladosporium cladosporioides BM-102 (Phylum Ascomycota) in a cluster oil well. DNA fingerprinting analysis using ERIC-PCR primers pairs also allowed us to detect the presence of R. mucilaginosa BM-104 right in the access of the studied naphtha system. Interestingly, R. mucilaginosa and C. cladosporioides were previously reported as predominant fungal contaminants of diesel and jet fuel and of kerosene and fuel storage systems, respectively. This paper represents the first evidence of fungal strains isolated and identified from the naphtha systems in the Venezuelan oil industry. The results obtained are discussed.
文摘The start and the course of bio-corrosion are conditioned by many factors which include biological effects like the influence of vegetation and microorganisms causing the deterioration of materials. The influence of bacteria causing the deterioration of concrete has been linked to the generation of biogenic sulphuric and nitric acids which originate in corrosion process by dissolution of calcium containing minerals from the concrete matrices. This paper primarily focuses on the investigation of influence of sulphur-oxidising bacteria Acidithiobacillus thiooxidans and sulphate-reducing bacteria Desulfovibrio desulfuricans at the resistance degree of cement composites. Various concrete composites with 5% addition of black coal fly ash as cement replacement as well as the reference samples without coal fly ash addition were studied in the experiments environments of sewage system proceeded during 90 days. The The laboratory experiments as well as experiments in situ in real corrosion was manifested by surface changes and weight changes of cement composites samples as well as changes in pH values of leachates. Considerable surface changes were detected in all investigated samples by microscopic methods. Crystals precipitated on concrete samples surface were identified by EDX as mixture of gypsum and ettringite. The roughness increases of surface of cement microscopy. composites were determined by confocal laser scanning
文摘The Buyeo Royal Tomb No. 1 is an ancient tomb built in the late 6<sup>th</sup> and early 7<sup>th</sup> century. The four walls of the main room have murals of four guardian deities, and the ceiling has murals of lotus and cloud patterns. This study assessed the optimal growth conditions of two fungal (Fusarium oxysporum, Mortierella sp.) and four bacterial (Bacillus cereus, Cupriavidus campinensis, Streptomyces avidinii, Streptomyces cirratus) strains isolated from the Tomb No. 1, along with their effects on the painting layer. The two fungi showed optimal growth at 20°C - 30°C under both nutrient and non-nutrient conditions. These strains did not decompose or discolor the three pigments (cinnabar, hematite, oyster shell white);however, M. sp. showed slight decomposition of the media (starch paste, sea weed). The four bacterial strains showed the most active growth at 20°C - 25°C under nutrient conditions and did not grow under non-nutrient conditions. These bacteria commonly degraded animal glue and sea weed components. In addition, S. cirratus degraded starch. The genus Streptomyces discolored the pigment medium to brown and black, suggesting a possible risk of discoloration of the murals. The current environment in Tomb No. 1 was sufficient for microorganism growth, and the presence of strains such as soil bacteria and actinomycetes on the mural surface may damage the murals. The findings of this study could be helpful for preserving mural tombs against biological damage caused by microorganisms that are already present or may be present in the tombs in the future. These findings also provide guidelines for comprehensive conservation management.
