Search results for "aspergillus"

Occurrence and Heterogeneity of Chymotrypsin Inhibitors in Vegetative Tissues of Barley

1977

Inhibitors of chymotrypsin and the alkaline proteinase of Aspergillus oryzae were present in the shoots of barley seedlings and weak activities were also detected in the shoot tops of 6-week-old plants. Treatments which induce inhibitor formation in tomato and potato leaves had no effect when tested on mature leaves, seedlings, or young tillers of barley. Fractionation experiments with isoelectric focusing showed that the barley leaves contained several proteinase inhibitors acting on both chymotrypsin and the Aspergillus proteinase, and one inhibitor which acted only on the Aspergillus enzyme. All of these inhibitors were different from the five Aspergillus proteinase inhibitors which are …

Isolierung und Charakterisierung einer Acetylester-Hydrolase aus Aspergillus rtiger / Isolation and Characterization of an Acetylester-Hydrolase from…

1980

Abstract The characteristic features of an acetic acid esters hydrolyzing enzyme (acetylesterase, EC 3.1.1.16) are described. The pH- and temperature optimum were 7.0 and 40 °C respectively. The stability of the enzyme regarding different pH- and temperature conditions was investigated. The molecular weight of the acetylesterase could be determined to 160000. A small acetic ester hydrolyzing activity was found too with a molecular weight of about 25000. The activity was not inhibited by addition of di-isopropylphosphorofluoridate (DFP) or physostigmine. The KM-value for glyceryl triacetate was about 90 mM. Concentration of the enzyme was done by ultrafiltration and column-chromatography. Th…

Isolation and characterization of a chlorogenic acid esterase from Aspergillus niger.

1980

Abstract The isolation and characterization of a specific chlorogenic acid esterase is described. The enzyme activity is measured by determination of the hydrolysis product caffeic acid. The enzyme had been concentrated by means of ultrafiltration and column-chromatography. The pH- and temperature optimum were 6.5 and 45 °C respectively. Divalent cations were not required for the enzyme activity. As other esterases, this enzyme is inhibited by di-isopropyl-phosphorofluoridate. The Km-value is 0.70 mᴍ chlorogenic acid, the molecular weight 240000. The described enzyme is specific for chlorogenic acid. On the other hand a typical unspecific esterase like the pig liver esterases does not split…

Résistance aux antifongiques azolés d’origine environnementale : quelles alternatives pour l’avenir ?

2015

Azole resistant Aspergillus fumigatus strains are increasingly reported in many countries. One resistance mechanism is attributed to the use of azole fungicides in environment. Two mutations, TR34/L98H and TR46/Y121F/T289A, on the cyp51A gene, have been described. Results of 40 publications about azole resistant strain detections, with TR34/L98H and TR46/Y121F/T289A mutations, in clinical and/or environmental samples, are presented in this review. These cases, observed in many countries, suggest spreading phenomenon. Measures to moderate fungicides treatments and/or alternative treatments in environment should be established to preserve the effectiveness of azole antifungal therapy for at-r…

Die Glucose-Oxydasen aus Penicillium notatum (Notatin) und Aspergillus niger (Nigerin) I. Isolierung und einige molekulare eigenschaften

1965

Summary By chromatography on carboxymethyl- and diethylaminoethyl-Sephadex pure preparations of the glucose oxidases ( β - d -glucose: oxygen oxidoreductase, EC 1.1.3.4) notatin from Penicillium notatum and nigerin from Aspergillus niger could be obtained. Differences in the binding to the cation- and anion-exchangers indicate that these two glucose oxidases differ markedly with respect to the structures of the respective apoenzymes. A mixture of notatin and nigerin can easily be separated by chromatography. Moreover, there are also structural differences in the neighbourhood of the prosthetic flavin-adenine dinucleotide groups. The flavin-adenine dinucleotide spectrum of notatin is shifted…

Trapping of Different Lipase Conformers in Water-Restricted Environments

1996

Based on a recently reported strategy to rationally activate lipolytic enzymes for use in nonaqueous media [Mingarro, I., et al. (1995) Proc. Natl. Acad. Sci. U.S.A. 92, 3308-3312], we compared the behavior in water-restricted environments of activated vs nonactivated forms of different lipases toward their natural substrates, triacylglycerols. To this end, nine lipases from varied origins (mammalian, fungal, and bacterial) were assayed using simple acidolyses as nonaqueous model reactions. The experimental results for several (though not all) lipases, discussed in the light of current structural and functional information, were collectively consistent with a model where, depending on the "…

Study on the reduction of acrylamide in mixed rye bread by fermentation with bacteriocin-like inhibitory substances producing lactic acid bacteria in…

2013

Abstract This study mainly focuses on a strategy for reducing of acrylamide in cereal products, predominantly in bakery products. The effect of mesophilic lactic acid bacteria (LAB) strains as well as a novel fermentation media on the bases of extruded rye wholemeal on the acrylamide formation in mixed rye bread of different weight of loaf was studied. The LC–MS/MS method for acrylamide determination in bread crumb has been applied. Addition of 15% low pH (pH 3.4–4.3) fermented product to bread dough, which were produced by using commercial strain Lactobacillus casei and bacteriocin-like inhibitory substances (BLIS) producing strains Lactobacillus sakei KTU05-6 , Pediococcus acidilactici KT…

Fungal Contaminants and Mycotoxins in Nuts

2021

Contamination by fungi and mycotoxins in nuts has achieved much attention in recent years. In fact, the fungal metabolites produced by the species of Aspergillus, Penicillium (aflatoxins and ochratoxins), Fusarium (trichothecenes, zearalenones and fumonisins) and Alternaria (alternariotoxins) with toxic and/or carcinogenic effects are considered a threat to human and animal health. In this chapter we will discuss the main fungal taxa and related mycotoxins most frequently associated with these materials. In this regard, the first results on the level of contamination by fungi and mycotoxins in samples of almonds and pistachios of different origins will be reported. The main strategies to re…

ASPERGILLI CONTAMINANTI DERRATE AD USO UMANO E ZOOTECNICO: attività enzimatica, tecniche diagnostiche innovative e possibili strategie di difesa biol…

2021

Towards Translational ImmunoPET/MR Imaging of Invasive Pulmonary Aspergillosis: The Humanised Monoclonal Antibody JF5 Detects Aspergillus Lung Infect…

2017

Invasive pulmonary aspergillosis (IPA) is a life-threatening lung disease of hematological malignancy or bone marrow transplant patients caused by the ubiquitous environmental fungus Aspergillus fumigatus. Current diagnostic tests for the disease lack sensitivity as well as specificity, and culture of the fungus from invasive lung biopsy, considered the gold standard for IPA detection, is slow and often not possible in critically ill patients. In a previous study, we reported the development of a novel non-invasive procedure for IPA diagnosis based on antibody-guided positron emission tomography and magnetic resonance imaging (immunoPET/MRI) using a [64Cu] DOTA-labeled mouse monoclonal anti…