No abstract

The use of red pigments linked to burial practices is widely documented in the Iberian prehistoric record and very often it has been traditionally interpreted as a ritual practice entailing the utilisation of local raw materials (iron oxides). Some research works, nevertheless, have also detected the use of red pigments which can only be interpreted as allochthonous. The red pigments spread over a single inhumation in a monumental Megalithic tomb surrounding Valencina de la Concepción Copper Age settlement was studied by means of X-ray diffraction, field emission scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray microfluorescence, micro-Raman and Fourier transform infrared spectroscopies. This approach allowed characterising the red pigments as cinnabar, mixed with tiny amounts of iron oxides. The presence of cinnabar, a product that was necessarily imported, in a context of an exceptional set of grave goods, suggests that the use of cinnabar was linked not only to ritual but also to practices related to the display of social status.

The aerobiology of caves in Southern Spain possesses special characteristics, different from caves located in Northern Spain. Previous studies demonstrated the influence of outdoor air on caves in the north and the existence of two different patterns, depending on the season. In summer there is an abundance of Ascomycota, whereas in winter Basidiomycota predominates, which are related to the periods of stagnation and ventilation, respectively. In caves in Southern Spain the presence of airborne Basidiomycota is scarce and Ascomycota represents the main group of fungi widely distributed across the caves in all seasons. The most characteristic features were the abundant presence of entomopathogenic fungi (Beauveria bassiana, Parengyodontium album, Pochonia chlamydosporia, Leptobacillium symbioticum, Leptobacillium leptobactrum) and Cladosporium cladosporioides in Cueva del Tesoro, Cueva de Ardales and Gruta de las Maravillas. However, the presence of yeasts of the genera Cutaneotrichosporon, Trichosporon, Cryptococcus, Naganishia, Cystobasidium, Microstroma and Phragmotaenium was exclusive to Gruta de las Maravillas. Fungal hazard in the three show caves were determined using an ecological indicator based on the concentration of spores in cave air.

Different Mediterranean Basin limestones, like Calcário Ançã (Portugal), Calcário Lioz (Portugal), Piedra San Cristobal (Spain), Piedra Escúzar (Spain) and Pietra di Lecce (Italy), have been widely used as building materials in the European architecture. The aim of this study was focused on biodeterioration, mainly on evaluation of the primary bioreceptivity of those materials. A set of samples was inoculated with a cultured photosynthetic biofilm under laboratory conditions. Several assessment tools were applied to monitor the colonization overtime of the different lithotypes. After 3 months of incubation the colonization occurred endolithically in some lithotypes, namely Piedra San Cristobal and Piedra Escúzar. Spectrophotometric determination of chlorophyll a was a useful analytical technique to achieve the total amount of photosynthetic biomass on rock substrates, demonstrating that Piedra Escúzar and Calcário Lioz were the highest and lowest bioreceptive lithotypes, respectively. Microscopic and image analyses were essential to understand the stone colonization process and its pattern of distribution. Physical stone parameters and exposure conditions were shown to play an important role in the establishment and development of photosynthetic colonization.

Rocks, either in natural geological outcrops or in stone monuments, are common habitats for a wide variety of microorganisms which colonize both rock surfaces and cracks. Physical properties such as porosity and surface roughness make limestone susceptible to biological colonization, which may induces aesthetic and/or physical and chemical damages. Organisms causing biodeterioration on monuments have usually been controlled by chemical products (biocides). In order to overcome the impact of these substances on the environment, human health and stone substrates, alternative tools such as natural products from plants or microorganisms can be used as an innovative approach for stone conservation. \ud \ud In this work, the efficiency of natural biocides (cells free culture filtrates of Trichoderna harzianum and Burkholderia gladioli, as well as glycoalkaloids from spontaneous Solanaceae) was tested under laboratory conditions against a multi-species phototrophic culture developing on Hontoria limestone. Their efficiency was assessed by digital image analysis, in vitro chlorophyll a quantification and confocal laser scanning microscopy. These techniques showed a good correlation, revealing that cells free filtrate of Trichoderma harzianum had an antagonistic action against the multi-species phototrophic culture tested in this work