Search results for "Aspergillus"
showing 10 items of 221 documents
Synthesis of Isomaltooligosaccharides by Saccharomyces cerevisiae Cells Expressing Aspergillus niger α‑Glucosidase
2017
The α-glucosidase encoded by the aglA gene of Aspergillus niger is a secreted enzyme belonging to family 31 of glycoside hydrolases. This enzyme has a retaining mechanism of action and displays transglycosylating activity that makes it amenable to be used for the synthesis of isomaltooligosaccharides (IMOs). We have expressed the aglA gene in Saccharomyces cerevisiae under control of a galactose-inducible promoter. Recombinant yeast cells expressing the aglA gene produced extracellular α-glucosidase activity about half of which appeared cell bound whereas the other half was released into the culture medium. With maltose as the substrate, panose is the main transglycosylation product after 8…
In vitro antifungal activity of bioactive peptides produced by Lactobacillus plantarum against Aspergillus parasiticus and Penicillium expansum
2017
Abstract Food spoilage caused by mycotoxigenic moulds represents an important problem in food security. The antimicrobial peptides are compounds of natural origin constituted by a variable number (5–100) of amino acids held together through peptide bonds. In this work, the cell free supernatants (CFSs) containing peptides obtained from four strains of LAB were lyophilized, filtered and tested to determine the antifungal activity against Aspergillus Parasiticus and Penicillium expansum . CFS obtained by Lactobacillus plantarum showed the highest inhibition activity. CFS was fractionated by size exclusion chromatography and injected into the liquid chromatography coupled to diode array detect…
Gaseous allyl isothiocyanate to inhibit the production of aflatoxins, beauvericin and enniatins by Aspergillus parasiticus and Fusarium poae in wheat…
2016
Abstract There is a growing concern about the presence of mycotoxins in foods, since up to 25% of cereals and cereal foods are contaminated with these compounds. Moreover, the general public is against the use of synthetic preservatives in foods and the use of natural antimicrobials in foods is a current trend. Allyl isothiocyanate (AITC) is a volatile antimicrobial derived from oriental and black mustard. The objective of this work was to evaluate the capacity of gaseous AITC in inhibiting the production of mycotoxins by Aspergillus parasiticus (aflatoxin producer) and Fusarium poae (beauvercin and enniatin producer) in wheat flour. Petri dish lids filled with 2 g of wheat flour were inocu…
Improvement of resveratrol production from waste residue of grape seed by biotransformation of edible immobilized Aspergillus oryzae cells and negati…
2017
Abstract A biotransformation method of producing resveratrol with immobilized Aspergillus oryzae negative pressure cavitation bioreactor (ICNPCB) with biphasic ionic liquid aqueous system pretreatment was investigated. Subsequently, the biotransformation conditions were optimized for the resveratrol production under types of ILs [C4MIM]Br, concentration of ILs 0.75 M, temperature 31 °C, ratios of solid to liquid 1:15 (mg/L), time 60 h and pH 6.0, the yield of resveratrol reached 224.61 ± 0.35 μg/g, which increased 4.36-fold to that of untreated one. The conversion rate of piceid reached 85.21%. The residual activity of immobilized microorganism was 82.26% after used for 15 runs. The develop…
Permanent Genetic Resources added to Molecular Ecology Resources Database 1 October 2009–30 November 2009.
2010
5 pages; International audience; This article documents the addition of 411 microsatellite marker loci and 15 pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Acanthopagrus schlegeli, Anopheles lesteri, Aspergillus clavatus, Aspergillus flavus, Aspergillus fumigatus, Aspergillus oryzae, Aspergillus terreus, Branchiostoma japonicum, Branchiostoma belcheri, Colias behrii, Coryphopterus personatus, Cynogolssus semilaevis, Cynoglossus semilaevis, Dendrobium officinale, Dendrobium officinale, Dysoxylum malabaricum, Metrioptera roeselii, Myrmeciza exsul, Ochotona thibetana, Neosartorya fisc…
Development of a Bioactive Sauce Based on Oriental Mustard Flour with Antifungal Properties for Pita Bread Shelf Life Improvement
2019
Ochratoxin A (OTA) is a mycotoxin produced in the secondary metabolism of fungus belonging to the genus Aspergillus and Penicillium. In this study, the employment of oriental mustard flour (OMF) as an ingredient in a packaged sauce was evaluated for the generation in situ of the antimicrobial compound allyl isothiocyanate (AITC) in order to preserve pita bread contaminated with Penicillium verrucosum VTT D-01847, an OTA producer, in an active packaging system. Four different concentrations (8, 16, 33 and 50 mg/g) were tested. Mycelium formation, mycotoxin production, AITC absorbed by the food matrix, and volatilization kinetics were studied for each concentration. The results obtained were …
Aflatoxins and A. flavus Reduction in Loaf Bread through the Use of Natural Ingredients
2018
In this study, the antifungal activity of yellow mustard (YMF) and oriental mustard (OMF) meal extracts against 14 strains of fungi was tested on a solid medium. The results obtained with the YMF were next confirmed in liquid medium determining the minimum inhibitory concentration (MIC) and the minimum fungicide concentration (MFC). Finally, the use of YMF as a natural preservative to extend the useful life of bread was evaluated. Breads with different concentrations of YMF (2, 4, 6 and 8 g/kg) were prepared and contaminated with Aspergillus flavus ISPA 8111 and Penicillium nordicum CECT 2320. For 10 days the formation of mycelium was observed, and after that the fungal growth and the mycot…
Active packaging with antifungal activities.
2016
International audience; There have been many reviews concerned with antimicrobial food packaging, and with the use of antifungal compounds, but none provided an exhaustive picture of the applications of active packaging to control fungal spoilage. Very recently, many studies have been done in these fields, therefore it is timely to review this topic. This article examines the effects of essential oils, preservatives, natural products, chemical fungicides, nanopartides coated to different films, and chitosan in vitro on the growth of moulds, but also in vivo on the mould free shelf-life of bread, cheese, and fresh fruits and vegetables. A short section is also dedicated to yeasts. All the ap…
First data on microflora of loggerhead sea turtle (Caretta caretta) nests from the coastlines of Sicily (Italy)
2020
ABSTRACT Caretta caretta is threatened by many dangers in the Mediterranean basin, but most are human-related. The purposes of this research were: (i) to investigate microflora in samples from six loggerhead sea turtle nests located on the Sicilian coast and (ii) to understand microbial diversity associated with nests, with particular attention to bacteria and fungi involved in failed hatchings. During the 2016 and 2018 summers, 456 eggs and seven dead hatchling from six nests were collected. We performed bacteriological and mycological analyses on 88 egg samples and seven dead hatchlings, allowing us to isolate: Fusarium spp. (80.6%), Aeromonas hydrophila (55.6%), Aspergillus spp. (27.2%) …
Mycotoxins in maize: mitigation actions, with a chain management approach
2020
Maize is the principal staple food/feed crop exposed to mycotoxins, and the co-occurrence of multiple mycotoxins and their metabolites has been well documented. This review presents the infection cycle, ecology, and plant-pathogen interactions of Aspergillus and Fusarium species in maize, and current knowledge on maize chain management to mitigate the occurrence of aflatoxins and fumonisins. Preventive actions include at pre-harvest, as part of cropping systems, at harvest, and at postharvest, through storage, processing, and detoxification to minimize consumer exposure. Preventive actions in the field have been recognized as efficient for reducing the entrance of mycotoxins into production…