Search results for "aspergillus"
showing 10 items of 221 documents
Nitric oxide radicals are emitted by wasp eggs to kill mold fungi
2019
Detrimental microbes caused the evolution of a great diversity of antimicrobial defenses in plants and animals. Insects developing underground seem particularly threatened. Here we show that the eggs of a solitary digger wasp, the European beewolf Philanthus triangulum, emit large amounts of gaseous nitric oxide (NO⋅) to protect themselves and their provisions, paralyzed honeybees, against mold fungi. We provide evidence that a NO-synthase (NOS) is involved in the generation of the extraordinary concentrations of nitrogen radicals in brood cells (~1500 ppm NO⋅ and its oxidation product NO2⋅). Sequencing of the beewolf NOS gene revealed no conspicuous differences to related species. However,…
pH control of the production of recombinant glucose oxidase in Aspergillus nidulans.
2004
Aims: Recombinant Aspergillus nidulans sVAL040, capable of synthesizing and secreting glucose oxidase derived from Aspergillus niger was used to study the influence of pH and carbon source on enzyme production. Methods and Results: Glucose oxidase gene (goxC) was expressed under transcriptional regulation by using the promoter of A. nidulans xlnB gene (encoding an acidic xylanase). A maximum specific glucose oxidase activity of approx. 10 U mg−1 protein and a maximum volumetric productivity of 29·9 U l−1 h−1 were obtained at pH 5·5, after 80 h of growth by using xylose as inducer. Enzyme volumetric productivity increased when xylans were used instead of xylose; however, specific glucose o…
Dynamics of fungal colonization in a new medical mycology laboratory
2012
International audience; Objective of the study. - Study of the spatio-temporal fungal colonization in a new medical mycology laboratory. Methods. - A 17-month survey of airborne fungal contamination was conducted in a new medical mycology laboratory at a tertiary care university hospital. This survey was implemented at three different periods: before the new premises were occupied (period A), during the move into the new laboratory (period B) and after resumption of the mycological activities in these new premises (period C). Results. - During period A, the airborne fungal load ranged from 2.3 to 6 cfu/m(3). The most frequently recovered airborne fungi were Penicillium spp. (75 to 100%). Du…
Differential susceptibility of mycotoxin-producing fungi to distinct antifungal proteins (AFPs).
2021
Abstract The global challenge to prevent fungal spoilage and mycotoxin contamination on foods and feeds require the development of new antifungal strategies. Filamentous fungi encode diverse antifungal proteins (AFPs), which offer a great potential for the control of contaminant fungi. In this study, four AFPs from Penicillium digitatum (PdAfpB) and Penicillium expansum (PeAfpA, PeAfpB and PeAfpC) belonging to classes A, B and C, were tested against a representative panel of mycotoxin-producing fungi. They included a total of 38 strains representing 32 different species belonging to the genera Alternaria, Aspergillus, Byssochlamys, Fusarium and Penicillium. PeAfpA exhibited a potent antifun…
Potential Application of Lactic Acid Bacteria to Reduce Aflatoxin B1 and Fumonisin B1 Occurrence on Corn Kernels and Corn Ears
2019
Fungal spoilage is an important issue for the food industry, leading to food sensory defects, food waste, economic losses and public health concern through the production of mycotoxins. Concomitantly, the search for safer natural products has gained importance since consumers began to look for less processed and chemically treated foods. In this context, the aim of this study was to evaluate the antifungal and antimycotoxigenic effect of seven strains of Lactobacillus plantarum. Lactic acid bacteria (LAB) were grown on Man Rogosa Sharpe (MRS) broth at 37 º
Antifungal effects of the bioactive compounds enniatins A, A1, B, B1
2010
To produce enniatin (ENs), Fusarium tricinctum CECT 20150 was grown in a liquid medium of potato (PDB), being mycotoxin purified by high performance liquid chromatography (HPLC) with a reverse phase semipreparative column using a mobile phase of acetonitrile/water using gradient condition. The purity of the ENs fractions was verified by analytical HPLC and LC/MS-MS. The pure fractions of ENs were utilized to study the biological activity on several mycotoxigenic moulds as Fusarium verticilloides, Fusarium sporotrichioides, Fusarium tricinctum, Fusarium poae, Fusarium oxysporum, Fusarium proliferatum, Beauveria bassiana, Trichoderma harzianum, Aspergillus flavus, Aspergillus parasiticus, Asp…
Evolution of emerging Fusarium mycotoxins contents throughout the shelf-life period of food
2014
which is cooked by steaming. It has been historically eaten in North African countries but nowadays its consumption is widely extended all around the world. As a cereal-based food, semolina is highly susceptible to contamination by mycotoxin-producing fungi. The presented procedure involves a modified QuEChERSbased extraction of 24 mycotoxins (15-ADON, 3-ADON, AFLAB1, AFLAB2, AFLAG1, AFLAG2, BEA, DON, DAS, ENA, ENA1, ENB, ENB1, FB1, FB2, FB3, FUSX, HT-2, NEO, NIV, OTA, STG, T2, ZEA) produced by Aspergillus, Penicillum and Fusarium fungi. The validation was performed by analyzing recovery samples at three different spiked concentrations with four replicates (n=4) at each concentration. Recov…
An Overview on the Status of Toxigenic Fungi and Mycotoxins in Spain
2004
Mycotoxins are a group of secondary metabolites which are produced by various filamentous fungi, and which can produce a toxic response in animals or humans after ingestion of contaminated food. The main toxigenic fungi isolated from foods and feeds belong to the genera Penicillium, Aspergillus, Fusarium and Alternaria. Spores of these moulds are almost universally present everywhere, they fall on plants and, under appropriate conditions, they can germinate and generate mycelia causing crop spoilage and/or production of mycotoxins.
Applications of flow cytometry to toxicological mycotoxin effects in cultured mammalian cells: a review.
2013
This review gives an overview of flow cytometry applications to toxicological studies of several physiological target sites of mycotoxins on different mammalian cell lines. Mycotoxins are secondary metabolites of fungi that may be present in food, feed, air and water. The increasing presence of mycotoxins in crops, their wide distribution in the food chain, and their potential for toxicity demonstrate the need for further knowledge. Flow cytometry has become a valuable tool in mycotoxin studies in recent years for the rapid analysis of single cells in a mixture. In toxicology, the power of these methods lies in the possibility of determining a wide range of cell parameters, providing valuab…
Evaluation of gaseous allyl isothiocyanate against the growth of mycotoxigenic fungi and mycotoxin production in corn stored for 6 months
2018
Brazil produces approximately 63 million tons of corn kernels annually, which is commonly contaminated with fungi and mycotoxins. The objective of this study was to evaluate the efficacy of gaseous allyl isothiocyanate (AITC) to inhibit the growth of Aspergillus parasiticus and Fusarium verticillioides, and mycotoxin production (aflatoxins B1 , B2 , G1 and G2 , fumonisins B1 and B2 ) in corn during 180 days of storage.; Results: AITC at 50 µL L-1 resulted in a significant reduction of the fungal population (P < 0.05) after 180 days, decreasing 3.17 log(CFU g-1 ) and 3.9 log(CFU g-1 ) of A. parasiticus and F. verticillioides respectively in comparison with the control. In addition, 10 and 50…