Professor in the Teaching Area of ​​Experimental Sciences, University of JaénFátima Aguilera Padilla does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.Universidad de Jaén provides funding as a member of The Conversation ES.Fungi, from the Latin fungus, are eukaryotic organisms that have characteristics of the plant kingdom (for example, they reproduce through spores) and the animal kingdom (they are heterotrophs, so they do not synthesize their own food).Since they cannot belong to two kingdoms at the same time, an exclusive club was created for them: the Fungi kingdom.These living beings colonized the Earth in the Ordovician, about 470 million years ago, long before human beings appeared, and they fulfill different types of missions.The kingdom of fungi is as extraordinarily diverse as it is unknown.Currently some 74,000 taxa have been described worldwide.It is estimated that, with the help of the application of techniques of molecular analysis and numerical taxonomy, that number will increase to one and a half million.Regarding their morphology, fungi are made up of filamentous structures called hyphae that intertwine with each other to form the mycelium.From this arise the reproductive structures, sometimes called fructifications.The best known are mushrooms (epigeal fungi, which rise to the surface of the earth when they mature to disperse their spores) and truffles (hypogeal fungi, which develop and mature underground).However, there are many microscopic fungi that do not develop these structures visible to the naked eye.The help of a microscope is necessary to observe them.If we refer to the role that fungi play in the food chain, we can distinguish, in general terms, three large groups:The symbiotics.They are those that establish mutually beneficial relationships with other species.The saprophytes.They break down dead organic matter.Parasites.They attack and cause damage to other living species of animals, plants or even other fungi.Two very important characteristics of fungi have been mentioned above: they are heterotrophic organisms that reproduce by spores.Spores are the fertile cellular structures of fungi, which, in most cases, are dispersed through the wind (figure 1).Aerobiology is the science that is responsible for the study of the presence and dispersion of biological particles in the air.One of the tasks of aerobiologists and aerbiologists is the identification and quantification of the presence of spores in the air, both indoors and outdoors.The spores, only visible through a microscope, have an external ornamentation that allows them to be identified and thus determine the species or taxonomic group from which they come.Some of these spores come from fungi that can cause biodeterioration, a term that refers to a complex phenomenon that involves alterations in the physicochemical and mechanical properties of materials induced by the growth of living organisms.If a traveling spore lands on a surface and the conditions are favorable for its germination (availability of nutrients, optimal conditions of temperature and humidity), a new mycelium will develop that will colonize the substrate, used by the fungus as food and support.At the right time it will bear fruit and give rise to spores that will be dispersed again.Thus begins once again the biological cycle of the fungus.The material cultural heritage is constituted, among others, by a great diversity of organic materials, such as paper, wood, different types of fabrics, leather, etc.That is, books, documents, clothing, pictures and wooden furniture, among others, are susceptible to being attacked by fungi, which use these substrates as a food source if environmental conditions are favorable (temperature of 25 ° C and relative humidity 60%).During the feeding and growth processes, the fungus releases enzymes and metabolites that chemically degrade the material on which it grows, while mechanically fragmenting the substrate.Consequently, it causes significant alterations in works of art, that is, it causes the biodeterioration of cultural and artistic heritage.There are numerous studies carried out inside archives, libraries and museums in order to analyze the presence of fungal spores in the air and determine the potential biological risk that the works preserved there could suffer.For example, an aerobiological analysis that we have recently carried out inside the museum of the cathedral of Jaén (figure 2) shows that more than 80% of the spores present in the air belong to species of fungi that, under favorable environmental conditions , can cause biodeterioration on the works, mostly made with materials of organic origin.The most frequently detected spores in these spaces belong to the genera Cladosporium, Aspergillus / Penicillium, and Alternaria, which can cause pigmentation changes (Figure 3) and surface erosion of colonized materials.Undoubtedly, there is a close relationship between mushrooms and cultural and artistic heritage.Aerobiological samplings make it possible to identify and quantify the presence of fungal spores in a given environment.These studies, integrated with the monitoring of environmental conditions, are very useful for making decisions about the most appropriate preventive measures against biodeterioration.The environment of libraries, archives and museums must be maintained in stable environmental conditions and within the correct ranges.In general, these buildings have air conditioning systems that, with proper and regular maintenance, allow control of the environment and avoid excessive peaks in temperature and humidity that could cause thresholds to be exceeded above which biodeterioration could pose a real risk. .It is also advisable to ventilate so that the air is in motion and remove the dust accumulated in these spaces regularly to avoid contamination of the environment.Therefore, it is necessary to frequently analyze the interior of the spaces intended for the conservation and storage of works of art in order to determine and avoid situations of biological risk.This allows us to preserve our cultural and artistic heritage in optimal conditions.Write an article and join a growing community of more than 138,700 academics and researchers from 4,229 institutions.Copyright © 2010–2021, The Conversation US, Inc.