Search results for "MYCELIUM"
showing 10 items of 83 documents
Reduction of the aflatoxins B1, B2, G1 and G2 in Italian piadina by isothiocyanates
2016
Abstract Aflatoxins (AFs) are mycotoxins produced mainly by the molds Aspergillus flavus , Aspergillus parasiticus and A . nomius . These mycotoxins are contaminants of cereals. AFB 1 , the most abundant and toxic metabolite, is known to cause several toxic responses, such as hepatotoxicity, teratogenicity and mutagenicity. Isothiocyanates (ITCs) are natural compounds produced by the enzymatic hydrolysis of glucosinolates (GLs), which have shown potent antimicrobial activity in food applications. In this study, ITCs derived from oriental and yellow mustard (0.1, 0.5 and 1 g of flour) were used to avoid the production of AFs in piadina (a typical Italian flatbread) contaminated with A . para…
Plasma modified PLA electrospun membranes for actinorhodin production intensification in Streptomyces coelicolor immobilized-cell cultivations
2017
Most of industrially relevant bioproducts are produced by submerged cultivations of actinomycetes. The immobilization of these Gram-positive filamentous bacteria on suitable porous supports may prevent mycelial cell-cell aggregation and pellet formation which usually negatively affect actinomycete submerged cultivations, thus, resulting in an improved biosynthetic capability. In this work, electrospun polylactic acid (PLA) membranes, subjected or not to O2-plasma treatment (PLA-plasma), were used as support for immobilized-cell submerged cultivations of Streptomyces coelicolor M145. This strain produces different bioactive compounds, including the blue-pigmented actinorhodin (ACT) and red-p…
The SCO1731 methyltransferase modulates actinorhodin production and morphological differentiation of Streptomyces coelicolor A3(2)
2018
AbstractStreptomyces coelicolor is a Gram-positive microorganism often used as a model of physiological and morphological differentiation in streptomycetes, prolific producers of secondary metabolites with important biological activities. In the present study, we analysed Streptomyces coelicolor growth and differentiation in the presence of the hypo-methylating agent 5′-aza-2′-deoxycytidine (5-aza-dC) in order to investigate whether cytosine methylation has a role in differentiation. We found that cytosine demethylation caused a delay in spore germination, aerial mycelium development, sporulation, as well as a massive impairment of actinorhodin production. Thus, we searched for putative DNA…
Inoculation of airborne conidia of Penicillium chrysogenum on the surface of a solid medium
2016
International audience; To reproduce a fungal contamination of food products by airborne conidia, a method to inoculate a few number (in the range 1-9) of conidia on the surface of agar media was developed. This technique would allow to determine accurately the time to detection of fungal colonies, then the mould free shelf-life of food products by using dry conidia. The method was based on dry-harvesting the conidia in the lid by gently taping the bottom of the dishes where sporulating mycelium was grown, retaining the conidia on glass beads, and, aseptically transferring the beads to successive Petri dishes to "dilute" the samples. Among the eleven factors tested by means of an experiment…
Modelling the effect of temperature, pH, water activity, and organic acids on the germination time of Penicillium camemberti and Penicillium roquefor…
2017
International audience; In this study, the influence of environmental factors on the germination time of Penicillium camemberti and Penicillium roqueforti conidia was evaluated. To do so, the effects of i/temperature, pH, water activity, and ii/organic acids were determined using models based on i/cardinal values, and ii/minimum inhibitory concentration (MIC) respectively. Cardinal values for germination of conidia were not observed to be species dependent. Minimum temperatures were estimated to be below the freezing point, with an optimum of 26.9 degrees C, and a maximum of 33.5 degrees C. For both species, minimal and optimal a(w) values were found to be 0.83 and 0.99, respectively, while…
The Candida albicans ENO1 gene encodes a transglutaminase involved in growth, cell division, morphogenesis, and osmotic protection
2018
Candida albicans is an opportunistic fungus that is part of the normal microflora commonly found in the human digestive tract and the normal mucosa or skin of healthy individuals. However, in immunocompromised individuals, it becomes a serious health concern and a threat to their lives and is ranked as the leading fungal infection in humans worldwide. As existing treatments for this infection are non-specific or under threat of developing resistance, there is a dire necessity to find new targets for designing specific drugs to defeat this fungus. Some authors reported the presence of the transglutaminase activity in Candida and Saccharomyces, but its identity remains unknown. We report here…
Effect of allyl isothiocyanate on transcriptional profile, aflatoxin synthesis, and Aspergillus flavus growth.
2020
Abstract The goals of this study were to determine the efficacy of allyl isothiocyanate (AITC) against the growth of A. flavus and Aflatoxin B1 (AFB1) production as well as to evaluate changes in the transcriptome profile when colonizing maize. A. flavus was inoculated in potato dextrose agar (PDA), the plates were placed inside glass jars and the mycelial growth (MG) was monitored for 7 d. Likewise, maize grains were contaminated with A. flavus in glass jars of 1 L and treated with 0.125, 0.25, 0.5, 1 and 5 µL of AITC. The moisture content (MC) of grains was 15 and 21%. After 7 days of storage, the MG was significantly reduced in doses higher than 0.125 µL/L of AITC. All doses of AITC redu…
Cell wall protein and glycoprotein constituents of Aspergillus fumigatus that bind to polystyrene may be responsible for the cell surface hydrophobic…
1996
Cell surface hydrophobicity (CSH) of Aspergillus fumigatus grown both in complex medium (yeast extract/peptone/dextrose; YPD) and minimal (Vogel's N) medium was monitored by assessing attachment of polystyrene microspheres to the cell surface. It was found that mature mycelium was hydrophobic. Treatment of intact mycelium with beta-mercaptoethanol (beta ME) abolished binding of the microspheres to hyphal elements, and coating of the microspheres with beta ME extracts from mycelium inhibited their attachment to intact mycelial cells. A. fumigatus mycelium was tagged in vivo with biotin and treated with beta ME. The beta ME extracts were analysed by SDS-PAGE and Western blotting with both per…
Growth characteristics of Aspergillus chevalieri and other fungi from under-coating of chocolate truffles
1997
Growth characteristics of fungi, which occasionally affected chocolate truffles, have been studied, using moulded and non-moulded samples. A whitish mycelial growth, located at the filling-coating interface is identified as Eurotium/Aspergillus chevalieri. The spores of other xerophilic molds (Aspergillus fumigatus, A. penicilloides and Penicillium verrucosum) were also found at the filling-coating interface. The water activity of chocolate coating was low enough to prevent fungal growth on the external surface of the truffles. However, the water activity of the filling, due to presence of cream, is sufficient enough to allow the growth of xerophilic moulds. The data on growth characteristi…
First Report of Southern Blight Caused by Sclerotium rolfsii on Hemp (Cannabis sativa) in Sicily and Southern Italy
2007
Hemp (Cannabis sativa L.), family Cannabaceae, is an annual herbaceous plant that is 1.5 to 4.0 m tall and native to the Caucasus Region, northern India, and Iran. It is cultivated in warm to temperate regions worldwide for its fiber, oil, and psychoactive substances. In Europe, commercial plantings have decreased from 52,872 ha in 1989 to 18,716 ha in 2005. Recently however, cultivation of hemp as a natural fiber species has been encouraged by European Union policy (2). During the summer of 2003, patches of dead plants were observed in test plots of 12 monoecious and dioecious hemp cultivars (Beniko, Epsylon 68, Felina 34, Ferimon, Fedora 17, Futura 75, Bialobrzeskie, Dioica 88, Fibranova…