Bioreceptivity of concrete: A review

Materials that support natural biodiversity on their surfaces can compensate for human activities that have a negative impact on nature and thus contribute to a carbon-neutral and nature-positive world. Specifically designing bioreceptive materials which favor the growth of biofilms on their surface is an approach complementing conventional, macroscopic green façades. But what exactly characterizes a bioreceptive substrate and how do biofilm and substrate interact? How and why does a spontaneous colonization and the formation of biofilms take place? What are biofilms and how can they be established in a laboratory setting? How can this existing knowledge be transferred to the artificial stone concrete so that this material can be tuned to increase (or decrease) its bioreceptivity? This review paper aims at summarizing the existing state of knowledge on bioreceptive concrete and pointing out inconsistencies and contradictions which can only be removed by more interdisciplinary research in the field

A procedure to evaluate the resistance to biological colonization as a characteristic for product quality of ceramic roofing tiles

9 pages, 5 figures, 4 tables, 22 references. The authors acknowledge the collaboration of the company Cerámica La Escandella (Spain) in supplying the samples of ceramic roofing tiles, and the advice and support by Dr. José Enrique Frias (Servicio de Cultivos Biológicos, Instituto de Biologia Vegetal y Fotosíntesis, CSIC, Seville, Spain) who provided us with the cyanobacterial strains used in this work.Ceramic roofing tiles suffer deterioration through time due to environmental exposure. Biological colonization affects the appearance and integrity of building materials, such as roofing tiles. The resistance to biocolonization represents an important property affecting the product quality of ceramic roofing tiles. While natural colonization of roofing tiles by organisms is a progressive, heterogeneous, and slow process, laboratory assessment of this phenomenon requires a sensitive procedure that can be carried out within a reasonable period of time. Different microorganisms have been evaluated and the use of phototrophs, specifically the cyanobacterium Oscillatoria, presented several advantages such as good adherence, homogeneous growth on surfaces, and the chlorophyll-autofluorescence which can be used for a sensitive detection. Colonization by Oscillatoria on roofing tiles was assessed by measuring the autofluorescence of cells. This study proposes the use of specific cyanobacterial cells and a simple method for monitoring biofilm formation and biological colonization of roofing tiles.. This study was funded by project PET2007-0080 from the Spanish Ministry of Science and Innovation.Peer reviewe

Bioreceptivity of concrete: A review

Materials that support natural biodiversity on their surfaces can compensate for human activities that have a negative impact on nature and thus contribute to a carbon-neutral and nature-positive world. Specifically designing bioreceptive materials which favor the growth of biofilms on their surface is an approach complementing conventional, macroscopic green façades. But what exactly characterizes a bioreceptive substrate and how do biofilm and substrate interact? How and why does a spontaneous colonization and the formation of biofilms take place? What are biofilms and how can they be established in a laboratory setting? How can this existing knowledge be transferred to the artificial stone concrete so that this material can be tuned to increase (or decrease) its bioreceptivity? This review paper aims at summarizing the existing state of knowledge on bioreceptive concrete and pointing out inconsistencies and contradictions which can only be removed by more interdisciplinary research in the field

Primary bioreceptivity of granitic rocks to phototrophic biofilms. Development of a bioreceptivity index

A comprehensive evaluation of the primary bioreceptivity to phototrophic biofilms of several varieties of granite was carried out. The bioreceptivity of the granites was more strongly affected by the physical characteristics of the stones than by their chemical composition. Growth of phototrophic biofilms was strongly enhanced by high open porosity, capillary water content and surface roughness. The findings of the study enabled us to develop a robust and well-founded bioreceptivity index (BI) for granitic rocks. The proposed BI has two components: BIgrowth, which quantifies the extent of the biological growth, and BIcolour, which quantifies the colour change undergone by the stone due to the colonisation and which can be considered the bioreceptivity perceptible by the human eye. The index was fitted to a qualitative scale of 0-10 and can therefore be used as a decision-making tool for selection of appropriate lithotypes for building and/or ornamental purposes

Bioreceptivity of Spruce Pine 87 Glass Batch by Fungi

A.Z.M. was supported by the Ramon y Cajal contract RYC2019-026885 from the Spanish Ministry of Science and Innovation (MCIN). S.G.-P. was supported by the intramural project PIE_20214AT021 from the Spanish National Research Council (CSIC). Publisher Copyright: © 2022 by the authors.The bioreceptivity, and the consequent biodeterioration of contemporary glass, used by artists worldwide, was studied. The two main objectives were: first, to verify if fungi with some culture media would produce more damages than the same fungi without a nutritional source, and to verify if the two genera of fungi produce the same damage on the same glass. Colourless glass samples with Spruce Pine 87 Batch (SPB-87) composition were inoculated with two distinct fungal species, Penicillium chrysogenum and Aspergillus niger, separately: (i) half with fungal spores (simulating primary bioreceptivity), and (ii) half with fungi in a small portion of culture media (simulating organic matter that can be deposited on exposed glassworks, i.e., secondary bioreceptivity). The alteration of glass surfaces were analysed by Optical Microscopy, SEM-EDS and µ-Raman. The mycelium of Penicillium chrysogenum generated a higher amount of fingerprints, stains and iridescence, whereas Aspergillus niger produced more biopitting and crystals on the glass surface. However, both species damaged the glass to different degrees in 4 and 6 months after the inoculation, producing physico-chemical damage (e.g., iridescence, biopitting), and chemical alterations (e.g., depletion and deposition of elements and crystals). The primary bioreceptivity experiment of glass samples inoculated with Aspergillus niger results in less damage than in the case of secondary bioreceptivity, being almost similar for Penicillium chrysogenum. The new and in-depth understanding of the bioreceptivity and deterioration of post-modern glass art and cultural heritage provided here is of paramount importance for the scientific, conservation and artistic communities—to protect glass cultural materials, or seen by artists as innovative and inspirational ways of creating glass art in the future.publishersversionpublishe

Cracks in consolidants containing TiO2 as a habitat for biological colonization: A case of quaternary bioreceptivity

The recently proposed concept of quaternary bioreceptivity applies to substrates treated with coating materials and it is considered in the present study with the alga Bracteacoccus minor and the cyanobacterium Nostoc sp. onto granite specimens treated with ethyl silicate and nano-sized silica doped with different amounts of TiO2 (0, 0.5, 1 and 3 wt%). The findings showed a lack of correlation between the amount of TiO2 and the level of colonization (main bioreceptivity estimator) to the presence of cracks on the surface, which annul the biocidal power of TiO2. Crack formation, which depends on the mechanical properties, greatly influences the bioreceptivity of the material. Thus, the cracks provided anchor points where water is retained, in turn strongly influencing the early stages of colonization kinetics, to a greater extent than the biocidal power of TiO2, which will probably increase as the biofilm develops over the entire surface. In addition, although the cracks were more abundant and wider in the ethyl silicate-based consolidant, the nano-sized silica provided better anchoring points, making the material treated with the corresponding consolidant more bioreceptiveS

Lithobiontic recolonization following cleaning and preservative treatments on the rock engravings of Valle Camonica, Italy: A 54-months monitoring

: Both the indirect control of microclimate conditions and the direct application of preservative products to contrast stone bioreceptivity may contribute to limit lithobiontic recolonization of cultural heritage surfaces after cleaning interventions. However, the priority deserved by these different preventive approaches has still been poorly evaluated, particularly in outdoor environments. This work dealt with the engraved sandstone surfaces of the National Park of Rock Engravings of Naquane (Italy, UNESCO WHS), widely colonized by lichens, mosses and a dark cyanobacterial biofilm, and thus requiring frequent cleaning interventions to preserve their legibility for visitors and scholars. In particular, post-cleaning recolonization by the different lithobionts was seasonally monitored along 54 months in different zones of an engraved outcrop, primarily differing in levels of shading, on parcels exposed to nine different conservative treatments. These included (or not) a pre-cleaning devitalization of lithobionts and the post-cleaning application of biocidal (benzalkonium chloride, plant essential oils, usnic acid) and other restoration products (nanocrystalline anatase, polysiloxane-based water repellent, ethyl-silicate-based consolidant). The combination of surface image analyses, fluorimetric and colorimetric measurements showed that mosses and the cyanobacterial biofilm rapidly recolonized all the parcels in the more shaded zone, irrespective of conservative treatments. In the other areas, recolonization significantly differed depending on the treatment. The post-cleaning application of biocides determined the best results through two vegetative seasons, but only nanocrystalline anatase and the polysiloxane-based water repellent maintained the surfaces lighter than uncleaned controls along the whole monitoring period. Recolonization primarily proceeded by the uncleaned surfaces surrounding the parcels and, at least in the examined case of lichens, did not show substantial shifts in community composition, although some nitrophytic species increased their frequency. In conclusion, the effectiveness of preservative treatments to prevent a rapid recolonization of heritage stone surfaces appeared subordinate to the presence of microenvironmental conditions less favourable to lithobionts

Review on the Influence of Biological Deterioration on the Surface Properties of Building Materials: Organisms, Materials, and Methods

A strong attention is recently paid to surface properties of building materials as these allows controlling solar gains of the building envelope and overheating of buildings and urban areas. In this regard, deterioration phenomena due to biological aggression can quickly damage solar-reflecting roof surfaces and thus increase sharply solar gains, discomfort, air-conditioning costs and waterproofing degradation. The same deterioration problem has deleterious effect on cultural heritage, ruining its huge historic and artistic value. This work is aimed at providing an overview on the different organisms that affect the surface of most used building materials, to support the design of new building materials with long-lasting surface properties and to find a way to preserve cultural heritage. Artificial ageing is the long-term aim of this investigation, in which what in nature happens after months or years is compressed in a very short time by forcing the growth of microorganisms through a strict control on the different conditioning factors. Both natural and artificial ageing are eventually outlined in the last part of this work to provide a comprehensive idea of what is necessary to study in a complete way biological ageing protocols on building materials. Several characterization techniques are also introduced to analyse the influence of microorganisms on the surface of different building materials

Influence of the intrinsic characteristics of mortars on their biofouling by pigmented organisms: Comparison between laboratory and field-scale experiments.

International audienceBiodeterioration of mortars by the photosynthetic microorganisms is affected by their intrinsic properties such as porosity, roughness and surface pH. The influence of these parameters was examined using an accelerated fouling test in laboratory and a natural fouling test in the real-world ( in situ). Based on color measurement and image analysis, the impact of each intrinsic parameter was evaluated. The results differed from a scale to the other one. No influence of porosity was measured on the algal colonization rate in the laboratory test whereas, a high porosity seemed to increase slightly the bioreceptivity of the mortars exposed outdoor. The roughness, in both tests, promoted the microbial colonization. However, the discrimination of roughness grades was better in the laboratory test than in the in situ one. The surface pH influenced remarkably on the accelerated biofouling test but not on the in situ one. These dissimilarities resulted from the differences in experimental configurations of the two tests