Applied microbiology and biotechnology in the conservation of stone cultural heritage materials (original) (raw)
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Application of Microbial Biotechnology in Conservation and Restoration of Stone Monument
Journal of Applied Biotechnology Reports, 2017
Treatments employed for the consolidation of monumental stones made of limestone due to incompatibility from the substrate and cement used for consolidation, plugging of pores induced by the new cement, leading to the acceleration of stone alteration. Microbial precipitation with a layer of calcium carbonate generated by bacteria might offer a solution to this dilemma because the layer would not block the natural pore structure, thus permitting free passage of soluble salts through the stone. In this study, an attempt has been made to provide an overview of the microbial induced carbonate precipitation as promising technology for bioremediation of such structures. At the first, the active microorganisms in the conservation of stone monuments transferred to the laboratory using the swap dipped in nutrient broth at a historic cemetery. After incubation and growth of colonies, Gram-positive bacilli were detected. Then pure single colonies were transferred to blood agar medium and incub...
Enzymatic Activity as a Measure of Total Microbial Activity on Historical Stone
Heritage, 2020
Stones of historical monuments exposed to the open air deteriorate over the course of time depending on physical, chemical, and biological factors acting in co-association. Among the biological factors, microorganisms play a key role in the deterioration process of stones. Detecting the level of microbial activity on stones is an essential step in diagnostic and monitoring studies of stone biodeterioration, and aids in controlling the performance of treatments applied to the stones. Therefore, this study aimed to develop a practical and rapid method for the determination of microbial activity on historical stones and use this method on the Mount Nemrut monuments (MNMs) (Adiyaman, Turkey). For that purpose, the fluorescein diacetate (FDA) hydrolysis method, frequently employed for soil environments, was adapted for the estimation and assessment of total microbial activity to understand whether microorganisms posed a potential risk for the biodeterioration of the limestones and sandst...
Journal of Cultural Heritage, 2022
Geochemical cycles result in the chemical, physical, and mineralogical modification of rocks, eventually leading to formation of soil. However, when the stones and rocks are a part of historic buildings and monuments, the effects are deleterious. In addition, microorganisms also colonize these monuments over a period of time, resulting in formation of biofilms; their metabolites lead to physical weakening and discoloration of stone eventually. This process, known as biodeterioration, leads to a significant loss of cultural heritage. For formulating effective conservation strategies to prevent biodeterioration and restore monuments, it is important to know which microorganisms are colonizing the substrate and the different energy sources they consume to sustain themselves. With this view in scope, this review focuses on studies that have attempted to understand the process of biodeterioration, the mechanisms by which they colonize and affect the monuments, the techniques used for assessment of biodeterioration, and conservation strategies that aim to preserve the original integrity of the monuments. This review also includes the Bomics^technologies that have started playing a large role in elucidating the nature of microorganisms, and how they can play a role in hastening the formulation of effective conservation strategies.
Bioremediation of weathered-building stone surfaces
Trends in Biotechnology, 2006
Atmospheric pollution and weathering of stone surfaces in urban historic buildings frequently results in disfigurement or damage by salt crust formation (often gypsum), presenting opportunities for bioremediation using microorganisms. Conventional techniques for the removal of these salt crusts from stone have several disadvantages: they can cause colour changes; adversely affect the movement of salts within the stone structure; or remove excessive amounts of the original surface. Although microorganisms are commonly associated with detrimental effects to the integrity of stone structures, there is growing evidence that they can be used to treat this type of stone deterioration in objects of historical and cultural significance. In particular, the ability and potential of different microorganisms to either remove sulfate crusts or form sacrificial layers of calcite that consolidate mineral surfaces have been demonstrated. Current research suggests that bioremediation has the potential to offer an additional technology to conservators working to restore stone surfaces in heritage buildings.
Bioconservation of Historic Stone Buildings—An Updated Review
Applied Sciences
Cultural heritage buildings of stone construction require careful restorative actions to maintain them as close to the original condition as possible. This includes consolidation and cleaning of the structure. Traditional consolidants may have poor performance due to structural drawbacks such as low adhesion, poor penetration and flexibility. The requirement for organic consolidants to be dissolved in volatile organic compounds may pose environmental and human health risks. Traditional conservation treatments can be replaced by more environmentally acceptable, biologically-based, measures, including bioconsolidation using whole bacterial cells or cell biomolecules; the latter include plant or microbial biopolymers and bacterial cell walls. Biocleaning can employ microorganisms or their extracted enzymes to remove inorganic and organic surface deposits such as sulfate crusts, animal glues, biofilms and felt tip marker graffiti. This review seeks to provide updated information on the ...
Role of Micro-Organisms in Biodeterioration of Sandstone in Heritage Buildings
Journal of Advanced Research in Construction and Urban Architecture, 2021
The growing concern for the preservation and protection of heritage building has led to a greater interest in the findings of biodeterioration occurring on these buildings. The cultural heritage objects are damaged by various agents like atmospheric agents, condensation or capillary humidity, temperature range, human action and microorganisms. A wide variety of organisms like bacteria, fungi, algae and plants etc. have been reported in the degradation of heritage structures. Microorganisms ability in production of pigments and organic acid plays a crucial role in discoloration and degradation of different types of stone in cultural heritage building objects. The study focuses on the types of microorganisms that are responsible for the biodeterioration of heritage buildings as well as the preventive measure and treatment done to restore the original form of the sandstone structures. The research is also supported and reinforced with a case study of Sher Shah Suri's tomb at Sasaram, Bihar.
Genetic characterization of microbial communities living at the surface of building stones
Letters in Applied Microbiology, 2009
Aims: The aim of the present study was to reveal the microbial genetic diversity of epilithic biofilms using a DNA-based procedure. Methods and Results: A DNA extraction protocol was first selected to obtain PCR-amplifiable metagenomic DNA from a limestone biofilm. Extracted DNA was used to amplify either 16S rRNA genes or ITS regions from prokaryotic and eukaryotic genomes, respectively. Amplified DNAs were subsequently cloned, amplified by colony PCR and screened by restriction analysis [restriction analyses of amplified ribosomal DNA (ARDRA)] for DNA sequencing. Phylogenetic analysis using 16S rDNA sequences showed that predominating bacteria were Alphaproteobacteria belonging to the genera Sphingomonas, Erythrobacter, Porphyrobacter, Rhodopila and Jannashia; Cyanobacteria and Actinobacteria were also identified. Analysis of ITS rDNA sequences revealed the presence of algae of the Chlorophyceae family and fungi related either to Rhinocladiella or to a melanized ascomycete. Statistical analysis showed that the specific richness evidenced was representative of the original sampled biofilm. Conclusions: The molecular methodology developed here constitutes a valuable tool to investigate the genetic diversity of microbial biofilms from building stone. Significance and Impact of the Study: The easy-to-run molecular method described here has practical importance to establish microbiological diagnosis and to define strategies for protection and restoration of stone surfaces.
Microbial Ecology
The deterioration of the stone built and sculptural heritage has prompted the search and development of novel consolidation/protection treatments that can overcome the limitations of traditional ones. Attention has been drawn to bioconservation, particularly bacterial carbonatogenesis (i.e. bacterially induced calcium carbonate precipitation), as a new environmentally friendly effective conservation strategy, especially suitable for carbonate stones. Here, we study the effects of an in situ bacterial bioconsolidation treatment applied on porous limestone (calcarenite) in the sixteenth century San Jeronimo Monastery in Granada, Spain. The treatment consisted in the application of a nutritional solution (with and without Myxococcus xanthus inoculation) on decayed calcarenite stone blocks. The treatment promoted the development of heterotrophic bacteria able to induce carbonatogenesis. Both the consolidation effect of the treatment and the response of the culturable bacterial community present in the decayed stone were evaluated. A significant surface strengthening (consolidation) of the stone, without altering its surface appearance or inducing any detrimental side effect, was achieved upon application of the nutritional solution. The treatment efficacy was independent of the presence of M. xanthus (which is known as an effective carbonatogenic bacterium). The genetic diversity of 116 bacterial strains isolated from the stone, of which 113 strains showed carbonatogenic activity, was analysed by repetitive extragenic palindromic-polymerase chain reaction (REP-PCR) and 16S rRNA gene sequencing. The strains were distributed into 31 groups on the basis of their REP-PCR patterns, and a representative strain of each group was subjected to 16S rRNA gene sequencing. Analysis of these sequences showed that isolates belong to a wide variety of phylogenetic groups being closely related to species of 15 genera within the Proteobacteria, Firmicutes and the Actinobacteria. This study shows that the abundant carbonatogenic bacteria present in the decayed stone are able to effectively consolidate the degraded stone by producing new calcite (and vaterite) cement if an adequate nutritional solution is used. The implications of these results for the conservation of cultural heritage are discussed.
Deterioration of Siliceous Stone Monuments in Latin America: Microorganisms and Mechanisms
Corrosion Reviews, 2004
1. Introduction 2. Organisms present in biofilms on historic, siliceous stone buildings of Latin America 3. The role of chemoautotrophic microorganisms in stone degradation: a historic paradigm 3.1. Organic acids 3.2. Polyfunctional acids and stone degradation 3.3. Alkaline degradation of siliceous stone 3.4. The role of osmolytes in stone degradation 3.5. Silicon metabolism 4. Conclusion 5. References ABSTRACT The microbial community present on and within stone monuments is highly varied and is subject to high and low temperatures. UV irradiation, and repeated desiccation. The mechanisms of the biodegradation of stone commonly thought to be important are acid-and base-induced dissolution of silica and mobilization of cations by chelation. The endolithic and epilithic microbial communities produce polyols as osmotic protectants (osmolytes) in response to desiccation. Low molecular weight polyols and polysaccharides (high molecular weight polyols) bind to the siloxane layers within layered 395