Cave biofilms: Characterization of phototrophic cyanobacteria and algae and chemotrophic fungi from three caves in Serbia

Cyanobacteria, algae (Chlorophyta and Bacillariophyta), and fungi were identified from biofilm samples from three caves in western Serbia: Ribnička, Hadž i Prodanova, and Rćanska. Temperature, light intensity, and relative humidity varied from 16.9 8C to 24.9 8C, 61% to 87%, and 215 Lux to 4400 Lux, respectively. In general, the highest number of documented taxa belonged to Cyanobacteria, with chroococcalean taxa prevailing and Gloeocapsa species as the most diverse. A large percentage of observed fungi were Ascomycetes or Zygomycetes, while the only representative of Basidiomycetes was Rhizoctonia s. lat. However, a redundancy analysis revealed that different taxonomic groups were dominant at different localities: cyanobacteria and fungi in Ribnička and Hadž i Prodanova, and Chlorophyta and Bacillariophyta in Rćanska. The statistical analysis showed that relative humidity is an important physical parameter influencing the development of various microbial communities in different caves. Cyanobacteria were mostly found in places with lower relative humidity, while Chlorophyta and Bacillariophyta were found in places with higher humidity. The documented physical parameters did not have a significant impact on the distribution of fungi. Measured chlorophyll-a content was highest on horizontal surfaces, where the highest content of organic/inorganic matter were also recorded. The highest water content was observed in biofilm samples from which many cyanobacteria taxa were identified

Wdrażanie metody bioluminescencyjnej w badaniach deterioracji zabytków jedwabnych poprzez działanie grzybów

Two silk artefacts from museum collections in Serbia, a silk icon from Petar Lubarda Legacy and a scroll made with traditional japanese techniques were analyzed for fungal presence. Fungi isolated from both the silk artefacts belonged to the genera Aspergillus, Chaetomium, Penicillium and Rhizopus. Actively growing colonies of Aspergillus and Penicillium species had caused chromatic alterations on the silk icon and their metabolic activity was demonstrated by high relative light unit values. In this research, measurement of the total microbial activity using the ATP bioluminescence method was used for the first time on silk artefacts and on textile in general. Scaning electron microscopy analysis of the scroll indicated that hyphae of Chaetomium globosum are capable of the mechanical deterioration of silk, as shown by the presence of cracks and gaps in silk fibres. This appears to be the first report of silk fibre degradation caused by C. globosum.Badano dwa jedwabne zabytki z kolekcji muzealnej w Serbii. Wyizolowano grzyby należące do rodzajów Aspergillus, Chaetomium, Penicillium i Rhizopus. Rosnące aktywnie kolonie Aspergillus i Penicillium spowodowały zmiany chromatyczne. Z analizy SEM wynika, iż niezależnie od zmian barwnych stwierdzono również uszkodzenia mechaniczne w postaci szczelin i pęknięć. Po raz pierwszy udało się zastosować metodę bioluminescencyjną przy badaniu tekstyliów. Są to pierwsze doniesienia o oddziaływaniu grzybów tego typu na tkaniny jedwabne

Sezonska raznovrsnost biodeteriogenih, patogenih i toksigenih gljiva u zraku sakralnoga objekta

The main purpose of this study was to isolate airborne fungi and assess seasonal variations in air contamination with their particulates by determining the levels of their propagules in the nave and exonarthex of a church. We also monitored indoor microclimate as a determining factor for fungal proliferation on wall paintings, spore release, and transmission through the air. The temperature and relative humidity of the nave favoured fungal growth. A total of 33 fungi were isolated, mainly of the phylum Ascomycota, and to the lesser extent of the phyla Zygomycota and Basidiomycota. The most common were the fungi of the genera Penicillium and Aspergillus (23.55 % and 20.58 %, respectively). Sørensen's quotient of similarity (0.37) suggests moderate species overlap and constant exchange of fungal propagules between the nave and exonarthex. The autumn had the highest diversity, with 17 documented taxa, followed by the summer and the winter. The spring had only eight taxa. Quantitative analysis of the airborne mycobiota in the nave (430±84.85 to 1880±106.07 CFU m -3 ) and exonarthex (715±59.62 to 2295±91.92 CFU m -3 ) showed very high contamination throughout the year, with values exceeding the maximum permissible concentrations by most standards. Many of the fungi determined in this study are known for their biodeteriogenic, toxigenic, and allergenic properties, and are a threat not only to occasional visitors and staff, but also to valuable works of art decorating nave walls. © 2018 Sciendo. All rights reserved. All Rights Reserved.Glavni cilj ovoga istraživanja bio je izolirati gljive iz zraka i procijeniti sezonske promjene u onečišćenju zraka gljivičnim propagulama u naosu i egzonarteksu istraživane crkve. Također su praćeni mikroklimatski parametri kao ograničavajući čimbenici za razvoj i rast gljiva na zidnim slikama, za oslobađanje spora i njihovu transmisiju kroz zrak. Zabilježena temperatura i relativna vlažnost zraka u naosu pogodovale su razvoju i rastu gljiva. Dokumentirana su 33 taksona gljiva, uglavnom pripadnika koljena Ascomycota, a manje su zastupljeni oni Zygomycota i Basidiomycota. Najčešće su bile prisutne plijesni rodova Penicillium (23,55 %) i Aspergillus (20,58 %). Sørensenov indeks sličnosti (0,37) upućuje na stalnu i umjerenu razmjenu gljivičnih propagula između naosa i egzonarteksa. Uzorci uzeti u jesen pokazali su najveću raznolikost sa 17 zabilježenih taksona, a oni uzeti u proljeće samo osam taksona. Kvantitativna mikološka analiza u naosu (430±84,85 do 1880±106,07 CFU m-3) i egzonarteksu (715±59,62 do 2295±91,92 CFU m-3) pokazala je visoku godišnju razinu onečišćenja zraka, s vrijednostima koje prema većini standarda prelaze dopuštene koncentracije. Mnoge identificirane gljive mogu dovesti do biodeterioracije, proizvesti mikotoksine i izazvati alergijske reakcije. Stoga su nepoželjne u sakralnim objektima ne samo zbog očuvanja murala nego i zbog zaštite zdravlja zaposlenih, posjetitelja i konzervatora

An Insight into an Olive Scab on the “Istrska Belica” Variety: Host‐Pathogen Interactions and Phyllosphere Mycobiome

The olive tree is one of the most important agricultural plants, affected by several pests and diseases that cause a severe decline in health status leading to crop losses. Olive leaf spot disease caused by the fungus Venturia oleaginea can result in complete tree defoliation and consequently lower yield. The aim of the study was to obtain new knowledge related to plant–pathogen interaction, reveal mechanisms of plant defense against the pathogen, and characterize fungal phyllosphere communities on infected and symptomless leaves that could contribute to the development of new plant breeding strategies and identification of novel biocontrol agents. The highly susceptible olive variety “Istrska Belica”' was selected for a detailed evaluation. Microscopy analyses led to the observation of raphides in the mesophyll and parenchyma cells of infected leaves and gave new insight into the complex V. oleaginea pathogenesis. Culturable and total phyllosphere mycobiota, obtained via metabarcoding approach, highlighted Didymella, Aureobasidium, Cladosporium, and Alternaria species as overlapping between infected and symptomless leaves. Only Venturia and Erythrobasidium in infected and Cladosporium in symptomless samples with higher abundance showed statistically significant differences. Based on the ecological role of identified taxa, it can be suggested that Cladosporium species might have potential antagonistic effects on V. oleaginea. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature