1,721,005 research outputs found
Dark-pigmented biodeteriogenic fungi in etruscan hypogeal tombs: New data on their culture-dependent diversity, favouring conditions, and resistance to biocidal treatments
No full textSubterranean Cultural Heritage sites are frequently subject to biological colonization due to the high levels of humidity, even in conditions of low irradiance and oligotrophy. Here microorganisms form complex communities that may be dangerous through mineral precipitation, through the softening of materials or causing frequent surface discolorations. A reduction of contamination’s sources along with the control of microclimatic conditions and biocide treatments (overall performed with benzalkonium chloride) are necessary to reduce microbial growths. Dark discolorations have been recorded in the painted Etruscan tombs of Tarquinia, two of which have been analyzed to collect taxonomical, physiological, and ecological information. Eighteen dark-pigmented fungi were isolated among a wider culturable fraction: nine from blackening areas and nine from door sealings, a possible route of contamination. Isolates belonged to three major groups: Chaetothyriales, Capnodiales (Family Cladosporiaceae), and Acremonium-like fungi. Exophiala angulospora and Cyphellophora olivacea, a novelty for hypogea, were identi!ed, while others need further investigations as possible new taxa. The metabolic skills of the detected species showed their potential dangerousness for the materials. Their tolerance to benzalkonium chloride-based products suggested a certain favouring effect through the decreasing competitiveness of less resistant species. The type of covering of the dromos may in"uence the risk of outer contamination. Fungal occurrence can be favoured by root penetration
Rock-inhabiting fungi and their role in deterioration of stone monuments in the Mediterranean area
No full textMost of the cultural heritage is in the Mediterranean area. Stone was historically the most durable and widely used building material; therefore, the greatest deal of antiques is represented by stone monuments located in outdoor environments. Atmospheric agents, pollution, and various stresses are the main causes of deterioration of artistic heritage as well as many micro-organisms that often cause irreversible damages. Conservation of this invaluable patrimony, therefore, is a demanding challenge. Rock-inhabiting fungi (RIF) are very active agents causing visible alteration patterns and exfoliation of stone monuments; ecological conditions in the Mediterranean rocks are optimal for RIF development. Along with environmental conditions, fungal colonization depends also on bioreceptivity of the surfaces and survival strategies of colonizing species. This paper represents an overview of RIF biodiversity on stone monuments known at present, mechanisms of attack and colonization and outdoor conditions allowing the settlement of RIF propagules, colonization, and the following biodeterioration processe
Coliphages as indicators of fecal contamination in sea water [I colifagi come indice di contaminazione fecale nelle acque marine]
No full textCARATTERIZZAZIONE MOLECOLARE DI FUNGHI MELANIZZATI ISOLATI DA ROCCE PROVENIENTI DA AMBIENTI ESTREMI. DATI PRELIMINARI
No full textAMBIENTE LITICO E SPECIAZIONE. CARATTERIZZAZIONE SU BASE MOLECOLARE DI UN NUOVO TAXON DI FUNGHI NERI MERISTEMATICI DI PROVENIENZA ALPINA
No full textRecolonization dynamics of marble monuments after cleaning treatments: A nine-year follow-up study
No full textThe prevention and control of biological patinas on outdoor stone monuments represent a demanding challenge for the conservation of cultural heritage also due to some microorganisms, particularly resistant to treatments, such as black meristematic fungi, an eco-physiological group well known for its tolerance to extreme conditions. Even if several methods and eco-friendly products have been proposed as new alternatives, traditional biocides are still far from being completely replaced. Recolonization is a natural process that occurs sooner or later after cleaning. The time that elapses until its occurrence can vary considerably depending on environmental conditions and the used products; unfortunately, the papers describing the effect of treatments over time are rare. This work aims to shed light on the recolonization process of marble surfaces in the ancient monumental cemetery of Bonaria (Cagliari) after nine years from treatments, evaluating the long-term efficiency of two different cleaning methods, namely dimethyl sulfoxide-based gel (DMSO-based gel) and Biotin T (a didecyldimethylammonium chloride-based product-). In this context, the microflora present before treatments and in the following years was assessed by culture-based methods and identified by molecular techniques, with attention on black meristematic fungi, which were used as reference for the most resistant lithobiontic organisms. Different environmental parameters, such as temperature, exposition, dominant winds, and rainfall, were considered, and infrared thermography, portable light microscopy, and image analysis were used. This research evidenced the influence of water availability and lightning in recolonization processes, the transition from the pioneer fungal community versus more resistant black fungal species after Biotin T treatment, and the long-lasting efficiency of the DMSObased gel. These findings prove that this low-impact method deserves more attention in the conservation of outdoor marble monuments, emphasizing the importance of long-term studies
Isolation and screening of fungi as potential degradors of volatile aromatic hydrocarbons
No full textEFFECT OF NIMODIPINE ON EXTRACELLULAR DOPAMINE LEVELS IN THE RAT NUCLEUS ACCUMBENS IN ETHANOL WITHDRAWAL
No full textRock black fungi: excellence in the extremes. From the Antarctic to Space
No full textThis work focuses on rock-inhabiting fungi (RIF) of Antarctic rocky deserts, considered the closest to a possible Martian habitat, as the best example of adaptation to the extremes. The study of RIF ecophysiology, resistance and adaptation provides tools that shed light on the evolution of extremophily. These studies also help define the actual limits for life and provide insight for investigating its existence beyond our planet. The scientific results obtained from over 20 years of research on the biodiversity, phylogeny and evolution toward extremotolerance reviewed here demonstrate how these fascinating organisms can withstand conditions well beyond those in their natural environment. A final focus is given on results and perspectives arising from a recent proteomic approach, and from astrobiological experiments and their significance for future space exploration. These studies demonstrate that Antarctic RIF offer an excellent opportunity to investigate many basic, but also applicative areas of research on extremophily
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