1,721,012 research outputs found
Studio sugli ifomiceti mediterranei. IV. Aspetti micofloristici ed ecologici dell'area protetta "Rifugio di Macchiagrande" di Focene(Roma)
No full textVengono riportate 177 specie di ifomiceti demaziacei rinvenuti su lettiera nell'Area Protetta "Rifugio di Macchiagrande" (Roma), di cui 31 nuovi per la micoflora italiana. Vengono inoltre fornite note ed illustrazioni di alcune specie ed una analisi statistica sulla loro distribuzione in varie tipologie ambiental
Studies on Mediterranean Hyphomycetes .1. Pseudospiropes dumeti sp nov
No full textA new dematiaceous Hyphomycete species, Pseudospiropes dumeti, found on dead wood of Pistacia lentiscus L. and Phillyrea latifolia L. in central Italy, is described acid illustrated
INTRODUZIONE ALLO STUDIO DEGLI IFOMICETI DEMAZIACEI PARTE 2° - CENNI DI BIOLOGIA ED ECOLOGIA
No full textFungal role in the movement, leaching and deposition of minerals across leaf litter and soil
No full textA considerable number of fungi have been described as having the power to translocate nutrients, but little is known about this role in the leaf litter-soil interface food web. A technique for evaluating the mechanisms of cellulose colonization by fungi and the changes in elemental composition of cellulose during its exploitation was set up. Ten sheets of pure cellulose (cotton linter) filter paper (10cm2) were layered to form a pad which was then inserted into a square-shaped terylene netting bag (15cm2), with a mesh size of 1mm2 . This package was then incubated for 6 months under leaf litter originating from an area of a low mixed Mediterranean maquis located in southern Italy (408570N; 138550E). Four different sites as field replicates were considered along three sampling times. The analysis of cellulose sheets by means of Scanning electron microscopy and EDS (Energy Dispersive X-ray spectroscopy) after 45, 180 and 600 days of field incubation has provided evidence of a progressive increase in the fragmentation of the niche represented by the cellulose itself in the course of proceeding of the decomposition. A clear change occurred in the content of trace elements during decomposition: two groups of elements were observed that seemed to have behaved differently over time. A larger group whose average concentration has been increasing with field incubation time was composed by Si, Fe, Al K, Cl, Mg. A second group of three elements (Ca, P and S) instead has followed a very different trend, increasing in some cases significantly and almost logarithmically between the first and the second sampling, and then remaining constant or even decreased (as in the case of Ca) between the second and the third sampling. The first group of microelements is clearly linked to the contribution of the soil (sandy), while the elements of the second group appeared correlated to biological activity. During the decomposition of cellulose Ca enters into fungal enzymatic mechanisms related to the tricarboxylic acid cycle (i.e. accumulation or precipitation of calcium oxalate in the environment); this can explain the peculiar behaviour of this element across the incubation time. The P and S are biogenic elements that enter directly in the composition of proteins and nucleic acids and other fundamental biological molecules (ATP , co-enzymes, structural proteins), and could be associated to the extent of fungal colonisation of cellulosic material. The results of the study provided evidence of a functional role of fungal hyphae and rhizomorphs in the movement, leaching and deposition of minerals across soil and leaf litter layers
Studies on Mediterranean Hyphomycetes .3. Quadracaea mediterranea anam-gen and sp nov
No full textQuadracaea mediterranea anam.-gen. et sp. nov., an hyphomycete recorded on leaves of Quercus ilex L. from central Italy, is described, discussed and illustrated, also by means of SEM
Biological invasion in the indoor environment : the spread of Eurotium halophilicum on library materials
No full textVolumes from an archive of the University of Milan showed whitish-grey discolouration putatively caused by microorganisms. Microscopic and viability assays proved that discolouration from two volumes were characterized by a marked presence of viable fungi, demonstrating that they were mainly biological in nature. Fungal sequences were phylogenetically most closely related to Eurotium, Aspergillus, Candida, Penicillium, Alternaria, Phaeosphaeria, Capnodiales and Pleosporales taxa. SEM analysis showed that Eurotium halophilicum is dominant on the two infected volumes. Viable airborne fungal loads near the two volumes were higher than recommended maximum values, demonstrating that airborne fungi could represent a source of risk. The airborne microbial community sampled in two different seasons was composed by fungi belonging in the genera Aspergillus, Candida and Eurotium. The detection of E. halophilicum also in the archival air indicated a possible source of contamination. Fluctuations of thermo-hygrometric values were also observed in the archive in the different seasons. The occurrence of white efflorescence on the stored volumes most likely depended on the lack of both a dusting programme and air-conditioning, and insufficient ventilation in the repository, and, on the hygroscopic behaviour of the binding materials used in the manufacture of the volumes
Electronic nose for the early detection of moulds in libraries and archives
No full textThe development of sensor technology has stimulated interest in the use of characteristic volatile and odorous compounds produced by fungi as early indicators of deterioration in materials. Sensor arrays to measure traces of volatile chemicals could detect early fungal growth in libraries and archives. In this study we tested an electronic nose to detect fungi actively growing on paper samples. The main aim was to verify whether or not a device, currently used to detect fungal activity in stored grain, might be suitable for detecting mould activity on paper. The findings indicate that it is possible to discriminate "in vitro" between paper samples affected by moulds and those unaffected, both at 100% RH (relative humidity), and at 75% RH, simply by measuring their odour fingerprint with an electronic nose. The sensors used in this study discriminated for each paper type three different species of actively growing fungi. Cluster analysis (CA) showed it was possible to differentiate between specific species. Different. paper types influenced the emission of odorous signals by moulds. When considering data from all the paper types, principal component analysis (PCA) indicated that only samples analysed at 100% RH could be separated. This study suggests that, before electronic-nose technology can be applied to the early detection of mould growth in libraries, archives, museums or in display cases, more information will be required on the influence of substrata and of other environmental parameters in the production of volatile chemicals by fungi
L'attività cellulosolitica della comunità edafica come misura sintetica di funzionalità ecosistemica
No full textAlla comunità batterica e fungina del suolo sono riconosciuti ruoli importanti quali il riciclo dei nutrienti, la funzione tampone rispetto ad eventi di inquinamento, il ruolo di contribuire alla capacità intrinseca di molti ecosistemi di essere resistenti o resilienti nei confronti di disturbi più o meno intensi. Il monitoraggio qualitativo e quantitativo dei cambiamenti cui incorrono le comunità edafiche è però complesso poiché l'entità e la struttura delle comunità di microrganismi del suolo sono per molti habitat ancora poco conosciute. Alcune funzioni fondamentali delle comunità del suolo (es. cellulolisi, ligninolisi, etc.), frutto della sinergia metabolica di più specie, possono misurare l'efficienza e la salute degli ecosistemi. Nel presente lavoro è stata studiata l'attività cellulosolitica in un suolo di ambiente mediterraneo al fine di comprendere e di prevedere, con opportuni modelli cinetici, le conseguenze degli stress ambientali sul ruolo della cellulosa nello stoccaggio o nel rilascio di anidride carbonica nell'atmosfera. La decomposizione in campo di campioni di cellulosa è stata accompagnata da misure del contenuto in microelementi (analisi EDS) e di colonizzazione da parte dei microrganismi del suolo (microscopia elettronica, metodi colturali e misure di biomassa). Il lavoro ha permesso di attribuire un ruolo funzionale alla successione con cui ha luogo la colonizzazione della riserva di carbonio organico nel suolo
Fungal biodeterioration of historical library materials stored in Compactus movable shelves
No full textIn the last ten years there have been many reports on single species mould infections within Compactus shelves in spite of conventional control of environmental temperature and humidity to recommended standars. Contamination was commonly characterized by white spots of mycelium observed on volume binding especially those of leather, parchment or textile. Until now, the identification of the causal agent at species level has not been reported. Using a range of sampling techniques, including adhesive tape and nitrocellulose membrane, and a combination of conventional culturing methods, direct microscopic observations and molecular methods, we have for the first time identified to the species level the fungus causing infections inside Compactus shelves. Th
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