In vitro antifungal and demelanizing activity of Nepeta rtanjensis essential oil against the human pathogen Bipolaris spicifera

The antifungal activity of Nepeta rtanjensis Diklić & Milojević essential oil was tested against the human pathogenic fungus Bipolaris spicifera (Bainier) Subramanian via mycelial growth assay and conidia germination assay. The minimally inhibitory concentration (MIC) of the oil was determined at 1.0 μg ml-1, while the MIC for the antifungal drug Bifonazole in a positive control was determined at 10.0 μg ml-1. The maximum of conidia germination inhibition was accomplished at 0.6 μg ml-1. In addition, at 0.6 μg ml-1 and 0.8 μg ml-1 the oil was able to cause morphophysiological changes in B. spicifera. The most significant result is the bleaching effect of the melanized conidial apparatus of the test fungi, since the melanin is the virulence factor in human pathogenic fungi. These results showed the strong antifungal properties of N. rtanjensis essential oil, supporting its possible rational use as an alternative source of new antifungal compounds

Biofilm forming cyanobacteria, algae and fungi on two historic monuments in Belgrade, Serbia

Biofilm on the sandstone substrata of the bridge 'Brankov most' and on the granite substrata of the 'Monument of the Unknown Hero' contains a complex consortia of cyanobacteria, algae, and fungi. Coccoid and filamentous cyanobacteria, green algae and diatoms make up the photosynthetic part of the biofilm while hyphal fragments, chlamydospores, fruiting bodies and spores take part as fungal components. These structures make a dense layer by intertwining and overlapping the stone surface. Five cyanobacterial, 11 algal and 23 fungal taxa were found. The interaction of the biofilm's constituents results in the bioweathering of the stone substrata through mechanical penetration, acid corrosion and the production of secondary mycogenic biominerals.

Mold attack on frescoes and stone walls of Gradac monastery

Microfungi can colonize stone surfaces and form sub-aerial biofilms which can lead to biodeterioration of historic monuments. In this investigation samples for mycological analyses were collected from stone material with visible alteration on stone walls of Gradac monastery exterior. The prevailing fungi found on stone walls were dematiaceous hyphomycetes with melanized hyphae and reproductive structures (Alternaria, Aureobasidium, Cladosporium and Epicoccum species). The frescoes inside the monastery building were also analyzed for the presence of mycobiota. The predominant fungi found on frescoes were osmophilic species from genera Aspergillus and Penicillium. The significant result is identification of human pathogen species Aspergillus fumigatus on frescoes

Comparison of anti-Aspergillus activity of Origanum vulgare L. essential oil and commercial biocide based on silver ions and hydrogen peroxide

The antifungal activities of Origanum vulgare essential oil (EO) and of a biocide based on silver and hydrogen peroxide (Sanosil S003) against seven Aspergillus species isolated from different substrata (stone, brick, silk and paper) of cultural heritage objects in Serbia were evaluated. Microdilution, agar dilution and microatmosphere methods were used to determine minimal fungistatic and minimal fungicidal concentrations (MIC and MFC), and light microscopy to determine structural abnormalities. MIC and MFC values for O. vulgare EO ranged from 0.2 to 5 mg mL−1 and for Sanosil S003 from 5 to 250 mg mL−1. Aspergillus sp. sect. fumigati was the most susceptible isolate, where MIC and MFC values were achieved at 0.5 mg mL−1 for O. vulgare EO, while MIC and MFC values for Sanosil S003 were achieved at 5 and 10 mg mL−1, respectively. Morpho-physiological changes were documented in all isolates, including lack of sporulation, depigmentation of conidiogenous apparatus and conidia, and presence of aberrant fungal structures. O. vulgare EO exhibited stronger anti-Aspergillus activity than Sanosil S003, as demonstrated by the higher MIC and MFC values and fewer morpho-physiological changes observed in the tested Sanosil S003 concentrations. O. vulgare EO could be an excellent alternative to commercial biocides, with high potential in the field of cultural heritage conservation

Antifungal activity of Nepeta rtanjensis essential oil

The chemical composition and antifungal activity of the essential oil of an endemic Serbian plant Nepeta rtanjensis Diklić & Milojević was studied. The essential oil was isolated from cultivated plants. Inhibition of mycelia growth of five micromycetes, two Alternaria species originally isolated from N. rtanjensis, Cladosporium cladosporoides, Trichoderma viride and Bipolaris spicifera, were tested using the agar dilution method. The essential oil of N. rtanjensis, the main component of which was 4aα,7α,7αβ-nepetalactone, showed strong antifungal activity against all the tested micromycetes. The minimum inhibitory concentration of N. rtanjensis essential oil ranged from 0.6 to 1.4 μg mL-1. The fungi most sensitive to the tested oil were Alternaria species, while Trichoderma viride was the most resistant.U ovom radu prezentovan je hemijski sastav i antifungalna aktivnost etarskog ulja endemične biljke Nepeta rtanjensis Diklić & Milojević. Etarsko ulje je izolovano iz kultivisanih biljaka. Inhibicija micelijalnog rasta pet mikromiceta, dve vrste roda Alternaria, izolovane sa N. rtanjensis, Cladosporium cladosporioides, Trichoderma viride i Bipolaris spicifera, testirana je makrodilucionom metodom. Etarsko ulje N. rtanjensis, čija je glavna komponenta 4aα,7α,7aβ-nepetalakton pokazuje jaku antifungalnu aktivnost u odnosu na sve testirane mikromicete. Minimalna inhibitorna koncentracija (MIC) etaskog ulja bila je u rasponu od 0,6 μg mL-1 do 1,4 μg mL-1. Najveću osetljivost na testirano ulje pokazale su vrste roda Alternaria dok je Trichoderma viride bila najotpornija.Projekat ministarstva br. 143041

Comparison of calibration factors for field-class dosimeters

This paper presents a comparison performed between two calibration laboratories in several radiation qualities, using dosimeters of varying quality as transfer instruments. The goal of this work was to investigate the viability of using field-class dosimeters for official comparisons and to determine if the calibration factors for field-class dosimeters are comparable between calibration laboratories within the stated measurement uncertainties. The results of the comparison were acceptable for high-quality electronic personal dosimeters in all radiation qualities, and such dosimeters could be used as transfer instruments. On the other hand, comparison results for low-quality dosimeters were often not acceptable, either due to pronounced energy dependence, low stability, or both. Such instruments are unreliable even under well-defined laboratory conditions, and their use in routine measurements may cause doubt in official data or influence public opinion. This problem is often hidden because many dosimeters are calibrated or verified only in 137Cs beams, where the deviations are the smallest. The largest differences are found for low-energy X-ray radiation qualities, where many dosimeters have significant overresponse

Positive Effects of the Caregiver Skill Training Program on Children With Developmental Disabilities: Experiences From Serbia

Background: Intervention programs for children with developmental disabilities increasingly target caregiver training to implement effective strategies for child development. Research conducted in different countries shows that the Caregiver Skills Training Program (CST) developed by the World Health Organization and Autism Speaks could also be a recommended intervention. Methods: The pre-pilot phase included seven, and the pilot phase included 29 families of children with developmental disabilities trained to implement the intervention program. The caregivers were asked to complete the Autism Treatment Evaluation Checklist at the beginning and at the end of the program. Results: In the pre-pilot phase, the Wilcoxon signed-rank test determined a statistically significant improvement in Speech, Language and Communication (z = −2.99, p < 0.05) and Health/Physical/Behavior (z = −2.375, p < 0.05) after caregiver participation in the training program. In the pilot phase, the paired t-test also determined a statistically significant improvement in Speech, Language and Communication between the first (M = 24.52, SD = 5.57) and the second testing (M = 25.66, SD = 6.11), t(28) = −2.29, p < 0.05, as well as a significant improvement between the first (M = 36.62; SD = 7.15) and the second testing (M = 35.38; SD = 5.91), t(28) = 2.11, p < 0.05 in Health/Physical/Behavior. Eta squared values (0.16 and 0.14) indicate that the intervention effect was significant. No differences were determined in Sociability and Sensory/Cognitive Awareness between the first and the second testing. Conclusion: The initial results of the Caregiver Skills Training Program are encouraging. For this program to be recommended as an evidence-based intervention, further research should be conducted on larger samples, controlling possible intervening variables

Fungal Deterioration of Cultural Heritage Objects

Significant percent of world cultural heritage artifacts is threatened by fungal infestation. Fungi can deteriorate different substrates via various physical and chemical mechanisms. Hyphal growth and penetration into the substrate can cause symptoms like discoloration, biopitting, cracking, exfoliation and patina formation. On the other hand, chemical mechanisms include acid secretion, release of extracellular enzymes, pigment production, oxidation/reduction reactions and secondary mycogenic minerals formation. These processes can lead to serious, both esthetic and structural, alterations which may be irreversible and could permanently impair artworks. Proper isolation and identification of autochthonous isolates, as well as employment of different microscopic techniques and in vitro biodegradation tests are pivotal in understanding complex biodeterioration mechanisms caused by microorganisms, including fungal deteriogens. Biodeterioration and biodegradation studies require multidisciplinary approach and close collaboration of microbiologists, chemists, geologists and different personnel responsible for the safeguarding of cultural heritage monuments and artifacts, especially restorers and conservators

Natural Deep Eutectic Solvent (NADES) Extraction Improves Polyphenol Yield and Antioxidant Activity of Wild Thyme (Thymus serpyllum L.) Extracts

Funding Information: info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F50006%2F2020/PT Funding: This research was supported by the Science Fund of the Republic of Serbia, 6060592, Natural Deep Eutectic Solvents for Green Agri-Food Solutions—DEStiny and 7750168, Novel extracts and bioactive compounds from under-utilized resources for high-value applications—BioUtilize. This project received funding from the European Union’s Horizon 2020—European Research Council (ERC)—under grant agreement No ERC-2016-CoG 725034. T Funding Information: This research was supported by the Science Fund of the Republic of Serbia, 6060592, Natural Deep Eutectic Solvents for Green Agri-Food Solutions?DEStiny and 7750168, Novel extracts and bioactive compounds from under-utilized resources for high-value applications?BioUtilize. This project received funding from the European Union?s Horizon 2020?European Research Council (ERC)?under grant agreement No ERC-2016-CoG 725034. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Wild thyme (Thymus serpyllum L.) herbal dust has been recognized as a potential underutilized resource for the recovery of antioxidants. The aim of this paper was to optimize natural deep eutectic solvent (NADES) extraction of polyphenols to obtain improved antioxidant activity of extracts determined by selected in vitro assays (DPPH, FRAP, and ABTS). Twenty different NADES systems were investigated in the first step of the screening of the extraction solvent and L-proline (Pro)–glycerine (Gly) based solvents provided the best results. Preliminary experiments organized by 25−1 fractional factorial design narrowed down the number of extraction factors from five (temperature, extraction time, NADES type, water content and L/S ratio) to three and determined their experimental domain for the final step. A face-centered central composite design with temperature (40–55–70 °C), extraction time (60–120–180 min) and L/S ratio (10–20–30 g NADES/g sample) was applied for influence analysis and process optimization. Multi-response optimization suggested a temperature of 65 °C, time of extraction of 180 min and L/S ratio of 28 g NADES/g DW as optimal extraction parameters. Experimental validation confirmed good agreement between experimental and predicted results in the extract obtained at optimal conditions and the interactions in the most suitable NADES (N16; Pro–Gly–H2O; 1:2:1) were confirmed by the1H-NMR.publishersversionpublishe

Diatoms on the green frogs skin (Pelophylax esculentus and P. ridibundus)

It is known that diatoms may be present on the skin of various animals (whales, dolphins, manatees, turtles…) (Frankovich et al. 2015, Wetzel et al. 2012). In our study diatoms were collected from the skin of two green frogs’ species: Pelophylax esculentus and P. ridibundus. Studied frogs were captured from the Special Nature Reserve “Deliblatska Pescara” at the locality Stevanove ravnice (Vojvodina province, Serbia). Two sampling methods were performed: (1) nonaggressive adhesive tape method (Urzì and de Leo 2001) and (2) scraping by toothbrush. In laboratory conditions, samples taken by the first method were stained with a drop of Lactophenol Cotton Blue and put on slides to be analyzed. Samples taken by the second method were treated by hot HCl and KMnO4 (Taylor et al. 2005) in order to obtain permanent slides. Light microscope observations and micrographs were made by Zeiss AxioImagerM.1 microscope with DIC optics (x1000 and x1600 magnification) and AxioVision 4.8 software. The present study describes diversity of diatoms from the green frog skin. According to literature data no studies have been published on diatoms living on the frog skin. Analysis of adhesive tape samples confirmed the presence of live diatom cells on the frog skin. Among them the most abundant were taxa from the genera Cocconeis, Epithemia, Gomphonema, Navicula and Rhopalodia. Presence of c. 30 diatom genera, such as Amphora, Craticula, Cymbella, Cymbopleura, Cymatopleura, Diploneis, Encyonema, Epithemia, Fallacia, Gomphonema, Luticola, Navicula, Neidium, Nitzschia, Pinnularia, Planothidium, Rhopalodia, Staurosira, Surirella, etc., was observed on permanent slides. The most dominant taxa were: Geissleria decussis sensu lato, Placoneis sp., Lemnicola hungarica, Cocconeis placentula var. lineate and Sellaphora bacillum. We consider that the great diversity and abundance of diatoms is consequence of their transfer from the environment (mud and macrophytes from eutrophic ponds) onto mucous frog skin. Highly mucous skin is an excellent environment which enables primary conditions for the survival of diatoms. Future research, especially under laboratory conditions, could show whether the frog skin is permanent or temporary diatom habitat