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

Supplementary data for the article: Janakiev, T.; Dimkić, I.; Unković, N.; Ljaljević Grbić, M.; Opsenica, D.; Gašić, U.; Stanković, S.; Berić, T. Phyllosphere Fungal Communities of Plum and Antifungal Activity of Indigenous Phenazine-Producing Pseudomonas Synxantha Against Monilinia Laxa. Frontiers in Microbiology 2019, 10. https://doi.org/10.3389/fmicb.2019.02287

Supplementary material for: [https://doi.org/10.3389/fmicb.2019.02287]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3729

Phyllosphere Fungal Communities of Plum and Antifungal Activity of Indigenous Phenazine-Producing Pseudomonas synxantha Against Monilinia laxa

European plum (Prunus domestica L.) is a significant commercial crop in Serbia in terms of total fruit production, and is traditionally processed into slivovitz brandy. The brown rot disease caused by Monilinia laxa drastically reduces plum yield almost every year. Fungal communities associated with leaves and fruits of four local Serbian plum cultivars (Požegača, Ranka, Čačanska Lepotica and Čačanska Rodna) were investigated in two phenological stages during early (May) and late (July) fruit maturation. Alpha diversity indices showed that fungal communities were heterogeneous and Beta diversity indicated that autochthonous fungal communities depended upon seasonal changes and the cultivars themselves. The phylum Ascomycota was the most abundant in all samples, with relative abundance (RA) between 46% in the Požegača cultivar (May) and 89% in the Lepotica cultivar (July). The most abundant genus for all plum cultivars in May was Aureobasidium, with RA from 19.27 to 33.69%, followed by Cryptococcus, with 4.8 to 48.80%. In July, besides Cryptococcus, different genera (Metschnikowia, Fusarium, and Hanseniaspora) were dominant on particular cultivars. Among all cultivable fungi, molecular identification of eleven M. laxa isolates from four plum cultivars was performed simultaneously. Bacterial isolates from the plum phyllosphere were tested for their potential antifungal activity against indigenous M. laxa isolates. The most potent antagonist P4/16_1, which significantly reduced mycelial growth of M. laxa, was identified as Pseudomonas synxantha. Further characterization of P4/16_1 revealed the production of volatile organic compounds and phenazine-1-carboxylic acid (PCA). Crude benzene extract of PCA exhibited 57–63% mycelial growth inhibition of M. laxa. LC/MS analysis of the crude extract confirmed the presence of phenazine derivatives amongst other compounds. Scanning electron microscopy revealed morpho-physiological changes in the hyphae of M. laxa isolates caused by the cell culture and the P. synxantha P4/16_1 crude benzene extract. This is the first report of antagonistic activity of P. synxantha against M. laxa induced by diffusible and volatile antifungal compounds, and it appears to be a promising candidate for further investigation for potential use as a biocontrol agent against brown rot-causing fungi.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3730

Morpho-physiological characteristics and interactions of isolates of Mycogone perniciosa (Magnus) Delacr

Mycogone perniciosa (Magnus) Delacr., which causes wet bubble disease of Agaricus bisporus Lange (Imb), results in a considerable crop loss on mushroom farms in Serbia. The isolation and identification of five isolates of M. perniciosa from diseased fruit bodies of white button mushroom from mushroom units in Serbia, Bosnia and Herzegovina and Holland were made. Morpho-physiological characteristics and inter-relationships of the obtained isolates were studied. Macroscopic and microscopic investigations of different zones between colonies of the isolates of M. perniciosa revealed the phenomenon of the hyphal interference between different isolates. The obtained results suggest that hyphal interference could serve as an additional parameter for a more reliable determination of fungal specifity.Mycogone perniciosa (Magnus) Delacr., izazivač oboljenja mokre truleži najčešći je uzročnik gubitaka u gajilištima Agaricus bisporus Lange (Imb) u Srbiji. Izvršena je izolacija i identifikacija 5 izolata M. perniciosa sa obolelih plodonosnih tela šampinjona iz gajilišta u Srbiji, Bosni i Hercegovini i Holandiji. Ispitivane su morfo-fiziološke karakteristike kao i stepen srodnosti proučavanih izolata na osnovu analize međusobnog delovanja kolonija, odnosno korišćenjem fenomena hifalne interferencije. Makroskopska i mikroskopska istraživanja odnosa izolata i dobijeni rezultati ukazuju da hifalna interferencija može predstavljati dodatni parametar u razlikovanju izolata M. perniciosa. Izolati dobijeni iz gajilišta u Srbiji slični su međusobno, kao i izolati iz Holandije koji su pokazali međusobnu sličnost ali se razlikuju od prethodnih. Izolati iz Bosne i Hercegovine razlikovali su se i od srpskih i od holandskih.Projekat ministarstva br. 14304

Morpho-physiological characteristics and interactions of isolates of Mycogone perniciosa (Magnus) Delacr

Mycogone perniciosa (Magnus) Delacr., which causes wet bubble disease of Agaricus bisporus Lange (Imb), results in a considerable crop loss on mushroom farms in Serbia. The isolation and identification of five isolates of M. perniciosa from diseased fruit bodies of white button mushroom from mushroom units in Serbia, Bosnia and Herzegovina and Holland were made. Morpho-physiological characteristics and inter-relationships of the obtained isolates were studied. Macroscopic and microscopic investigations of different zones between colonies of the isolates of M. perniciosa revealed the phenomenon of the hyphal interference between different isolates. The obtained results suggest that hyphal interference could serve as an additional parameter for a more reliable determination of fungal specifity.Mycogone perniciosa (Magnus) Delacr., izazivač oboljenja mokre truleži najčešći je uzročnik gubitaka u gajilištima Agaricus bisporus Lange (Imb) u Srbiji. Izvršena je izolacija i identifikacija 5 izolata M. perniciosa sa obolelih plodonosnih tela šampinjona iz gajilišta u Srbiji, Bosni i Hercegovini i Holandiji. Ispitivane su morfo-fiziološke karakteristike kao i stepen srodnosti proučavanih izolata na osnovu analize međusobnog delovanja kolonija, odnosno korišćenjem fenomena hifalne interferencije. Makroskopska i mikroskopska istraživanja odnosa izolata i dobijeni rezultati ukazuju da hifalna interferencija može predstavljati dodatni parametar u razlikovanju izolata M. perniciosa. Izolati dobijeni iz gajilišta u Srbiji slični su međusobno, kao i izolati iz Holandije koji su pokazali međusobnu sličnost ali se razlikuju od prethodnih. Izolati iz Bosne i Hercegovine razlikovali su se i od srpskih i od holandskih.Projekat ministarstva br. 14304

Fungal colonization of air-conditioning systems

Fungi have been implicated as quantitatively the most important bioaerosol component of indoor air associated with contaminated air-conditioning systems. rarely, indoor fungi may cause human infections, but more commonly allergenic responses ranging from pneumonitis to asthma-like symptoms. From all air conditioner filters analyzed, 16 fungal taxa were isolated and identified. Aspergillus fumigatus causes more lethal infections worldwide than any other mold. Air-conditioning filters that adsorb moisture and volatile organics appear to provide suitable substrates for fungal colonization. It is important to stress that fungal colonization of air-conditioning systems should not be ignored, especially in hospital environments

FUNGAL COLONIZATION OF AIR-CONDITIONING SYSTEMS

Abstract — Fungi have been implicated as quantitatively the most important bioaerosol component of indoor air associated with contaminated air-conditioning systems. Rarely, indoor fungi may cause human infections, but more commonly allergenic responses ranging from pneumonitis to asthma-like symptoms. From all air conditioner filters analyzed, 16 fungal taxa were isolated and identified. Aspergillus fumigatus causes more lethal infections worldwide than any other mold. Air-conditioning filters that adsorb moisture and volatile organics appear to provide suitable substrates for fungal colonization. It is important to stress that fungal colonization of air-conditioning systems should not be ignored, especially in hospital environments

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

Molds in museum environments: Biodeterioration of art photographs and wooden sculptures

Pieces of art stored in museum depots and display rooms are subject to fungal colonization that leads to bio-deterioration processes. Deteriorated wooden sculptures and art photographs temporarily stored in the quarantine room of the Cultural Center of Belgrade were subject to mycological analyses. Twelve fungal species were identified on the wooden substratum and five species were detected on photograph surfaces. Trichoderma viride, Chaetomium globosum and Alternaria sp. were the fungi with proven cellulolytic activity detected on the examined cellulose substrata. Indoor air mycobiota were estimated to 210.09 ± 8.06 CFU m-3, and the conidia of fungus Aspergillus niger were the dominant fungal propagules in the air of the examined room. [Projekat Ministarstva nauke Republike Srbije, br. 173032