H Kashiwadani

Bio: H Kashiwadani is an academic researcher. The author has contributed to research in topics: Lichen. The author has an hindex of 2, co-authored 2 publications receiving 58 citations.

Biodeterioration of stone in relation to microclimate in the Ta Nei Temple – Angkor (Cambodia)

Abstract: In the favourable tropical climatic conditions of Angkor, Khmer temples, which have been abandoned for many centuries, have been suffered from a wide range of biodeterioration processes. Ta Nei temple, which is still surrounded by a luxuriant forest, was selected as an appropriate site for testing the influence of microclimate on stone conservation. Not only big trees are growing on and all around the monument, but also different patinas of algae and cyanobacteria, lichens, mosses and higher plants are colonizing the temple stones. Field observations and laboratory analyses were carried out to establish the different phenomenologies of biodeterioration, their frequency and distribution in relation to water percolation, shadowing, ventilation and typology of stone. Data on the variations of these communities were collected in the field and evaluated on the basis of the ecology of the species. These data were related to temperature, light, ventilation and relative humidity measured in the site and gave rise to the identification of a clear ecological trend of different biological communities. The first colonizing community, which start to grow with minimum level of water in the substrate, is the Trentepohlietum, a pioneer coenosis widely spread in relatively xeric and shady conditions. It is followed by the Scytonemo-Gloeocapsetum in conditions of increasing water and light and then by various lichen communities (with dominance of Lepraria and Pyxine). With progressive higher water content of the substrate, communities of mosses and ferns colonize and grow on the stone. As noticed for other monuments, when the dynamism is blocked or limited by edaphic factors, these deterioration patterns change according to the environmental factors and not as successional stages. The knowledge of these relationships is very useful for evaluating the feasible use of indirect control methods against the various biological colonizers, and therefore for establishing the best microclimatic conditions for stone conservation.

Microbial deterioration and sustainable conservation of stone monuments and buildings

Abstract: Geomicrobially induced deterioration of stone monuments and buildings contributes to a considerable loss of world cultural heritage, especially when exposed to a changing climate or environment. The active biodeterioration processes typically involve biochemical activities and cooperation among functional microorganisms in epilithic biofilms, which assimilate mineral nutrients and metabolize anthropogenic pollutants through biogeochemical cycles. Development of any effective mitigation strategies requires the comprehensive understanding of such processes. We focus on how microbes contribute to the biodeterioration processes through their activities and biogeochemical cycles of elements, discuss biochemical mechanisms involved and provide innovative strategies for sustainable conservation of stone monuments and buildings. Biodeterioration of stone monuments and buildings can lead to a loss of world cultural heritage. This Review discusses the role of microbes in the deterioration processes, the biochemical mechanisms involved and possible strategies for sustainable conservation of stone monuments and buildings.

Metabolomic and high-throughput sequencing analysis—modern approach for the assessment of biodeterioration of materials from historic buildings

Abstract: Preservation of cultural heritage is of paramount importance worldwide. Microbial colonization of construction materials, such as wood, brick, mortar, and stone in historic buildings can lead to severe deterioration. The aim of the present study was to give modern insight into the phylogenetic diversity and activated metabolic pathways of microbial communities colonized historic objects located in the former Auschwitz II-Birkenau concentration and extermination camp in Oświecim, Poland. For this purpose we combined molecular, microscopic and chemical methods. Selected specimens were examined using Field Emission Scanning Electron Microscopy (FESEM), metabolomic analysis and high-throughput Illumina sequencing. FESEM imaging revealed the presence of complex microbial communities comprising diatoms, fungi and bacteria, mainly cyanobacteria and actinobacteria, on sample surfaces. Microbial diversity of brick specimens appeared higher than that of the wood and was dominated by algae and cyanobacteria, while wood was mainly colonized by fungi. DNA sequences documented the presence of 15 bacterial phyla representing 99 genera including Halomonas, Halorhodospira, Salinisphaera, Salinibacterium, Rubrobacter, Streptomyces, Arthrobacter and nine fungal classes represented by 113 genera including Cladosporium, Acremonium, Alternaria, Engyodontium, Penicillium, Rhizopus, and Aureobasidium. Most of the identified sequences were characteristic of organisms implicated in deterioration of wood and brick. Metabolomic data indicated the activation of numerous metabolic pathways, including those regulating the production of primary and secondary metabolites, for example, metabolites associated with the production of antibiotics, organic acids and deterioration of organic compounds. The study demonstrated that a combination of electron microscopy imaging with metabolomic and genomic techniques allows to link the phylogenetic information and metabolic profiles of microbial communities and to shed new light on biodeterioration processes.

The Role of Fungi and Lichens in the Biodeterioration of Stone Monuments

Abstract: This review elucidates current knowledge on the significant role of fungi and lichens in the biodeterioration of stone monuments. The effect caused by many epilithic lichen species in the deterioration of different types of stone has been extensively investigated and demonstrated. Nonetheless, many aspects of the deterioration mechanisms of microcolonial fungi (MFC) and endolithic lichens are still to be proved. An interesting hypothesis has recently been put forward involving the secretion of siderophores like compounds. Lichens can provide bioprotection for stone surfaces, acting as a barrier against weathering, retaining moisture, increasing waterproofing, reducing thermal stress and erosion, and absorbing pollutants. Nevertheless, the evaluation of biodeterioration vs. bioprotection cannot be generalised, since it can vary according to the behaviour of different species, as well as being affected by both the lithotype and the environment. In addition to the laboratory studies, more field studies of biological communities are required, to analyse their establishment and succession in natural conditions and after conservation treatments. In order to guarantee the best decision for stone conservation, cleaning operations should not be based on a generalised approach, but should rather be based on a careful evaluation of different aspects concerning biodeterioration and bioprotection.