Search results for "Vitis"

Potential application of lactic acid bacteria in the biopreservation of red grape from mycotoxigenic fungi

2021

Background Filamentous fungi are the main contamination agent in the viticultural sector. Use of synthetic fungicides is the regular answer to these contaminations. Nevertheless, due to several problems associated with the use of synthetic compounds the industry demands new and safer methods. In the present work, the biopreservation potential of four lactic acid bacteria (LAB) strains was studied against the principal grape contaminant fungi. Results Agar diffusion test evidenced that all four culture-free supernatant (CFS) had antifungal properties against all tested fungi. The Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) test values evidenced that medi…

Factors affecting the presence of ochratoxin A in wines.

2006

Ochratoxin A (OTA) are synthesized mainly by different species of Aspergillus and Penicillium being its human toxicological effects reflected in different countries due to the consumption of different foods and beverages such as red, white, rose, and special wines. This review presents an overview of the direct (meteorological conditions, grape cultivation, and wine-making techniques) and indirect (latitude, year of production, use of pesticides, presence of spoilage microorganisms, conditions of storage of the harvested grapes, type of maceration, and conditions of fermentation), factors affecting the presence of OTA in wines.

Study of Spanish grape mycobiota and ochratoxin A production by Isolates of Aspergillus tubingensis and other members of Aspergillus section Nigri.

2005

ABSTRACT The native mycobiota of five grape varieties grown in Spain has been studied. Four (Bobal, Tempranillo, Garnacha, and Monastrell) were red varieties and one (Moscatel) was white. The main fungal genera isolated were Alternaria , Cladosporium , and Aspergillus . The isolation frequency of Aspergillus spp. section Nigri in contaminated samples was 82%. Ochratoxin A (OTA) production was assessed using yeast extract-sucrose broth supplemented with 5% bee pollen. Cultures of 205 isolates from this section showed that 74.2% of Aspergillus carbonarius and 14.3% of Aspergillus tubingensis isolates produced OTA at levels ranging from 1.2 to 3,530 ng/ml and from 46.4 to 111.5 ng/ml, respecti…

Molecular characterization of the black Aspergillus isolates responsible for ochratoxin A contamination in grapes and wine in relation to taxonomy of…

2009

This work examines ochratoxigenic mycobiota in grapes by ap-PCR analysis sequence analysis of the ITS and IGS regions and ability to produce OTA. A comparison was also made with many reference strains of Aspergillus section Nigri. Based on ap-PCR profiles, derived from two microsatellite primers, three main groups were obtained by UPGMA cluster analysis corresponding to A. carbonarius, A. niger and A. tubingensis. The cophenetic correlation values corresponding to ap-PCR UPGMA analysis revealed a higher genetic variability in A. niger and A. tubingensis than in A. carbonarius. In addition, no genotypical differences could be established between OTA producers and nonproducers in all species …

Real-time PCR based procedures for detection and quantification of Aspergillus carbonarius in wine grapes

2008

9 pages, 4 tables, 1 figure.

Effect of carbendazim and physicochemical factors on the growth and ochratoxin A production of Aspergillus carbonarius isolated from grapes.

2007

Carbendazim is a systemic fungicide that is commonly used on several crops (tobacco, fruit, vegetables, cereals, etc.). This fungicide is used to control fungal infections in vineyards. It is indicated against Botrytis cinerea, Uncinula necator, Plasmopara viticola and other fungi and can be used either alone or coupled with other fungicides. However, there is a lack of in-depth studies to evaluate its effectiveness against growth of Aspergillus carbonarius isolated from grapes and OTA production. A medium based on red grape juice was used in this study. Preliminary studies were performed at 0.98 a(w) and 25 degrees C using carbendazim concentrations over a wide range (1-2000 ng/ml medium) …

A polyphasic approach to the identification of ochratoxin A-producing black Aspergillus isolates from vineyards in Sicily.

2008

Aspergillus strains belonging to section Nigri isolated during a two year survey in eight Sicilian vineyards located on the slopes of Mount Etna (Sicily, Italy) were analysed analyzed in order to characterize species responsible for ochratoxin A (OTA) contamination of grapes. The polyphasic approach permitted analysis of biodiversity of Aspergillus isolates in relation to their morphology, ochratoxigenicity and genetic variability. We assessed OTA production by A. carbonarius, A. niger, A. tubingensis and A. japonicus using an enzyme-linked immunosorbent assay. A. carbonarius isolates were the strongest OTA producers. A subset of 66 representative strains was selected for further DNA-based …

Predictive assessment of ochratoxin A accumulation in grape juice based-medium by Aspergillus carbonarius using neural networks

2009

Aims: To study the ability of multi-layer perceptron artificial neural networks (MLP-ANN) and radial-basis function networks (RBFNs) to predict ochratoxin A (OTA) concentration over time in grape-based cultures of Aspergillus carbonarius under different conditions of temperature, water activity (a(w)) and sub-inhibitory doses of the fungicide carbendazim. Methods and Results: A strain of A. carbonarius was cultured in a red grape juice-based medium. The input variables to the network were temperature (20-28 degrees C), a(w) (0 center dot 94-0 center dot 98), carbendazim level (0-450 ng ml(-1)) and time (3-15 days after the lag phase). The output of the ANNs was OTA level determined by liqui…

Use of Optical Coherence Tomography in Patients with Desquamative Gingivitis: A Case Series

2019

Palatal fenestration after orthodontic treatment. Intermodal approach and evolution. A case report

2018

A 15-year-old patient is referred to the Department of Periodontics of the University of Valencia. The patient reported dissatisfaction with the position of upper right canine after orthodontic treatment. Previously, in a private center, surgical approaches were performed for the traction of the canine included. On clinical examination at first appointment, generalized plaque-induced gingivitis was observed, with palatal fenestration of the root of upper right lateral incisor of approximately 75% of the total surface, with suppuration and very little gingiva inserted at the cervical level, which presents a buccal torque of the crown. Radiologically, a mild rhizolysis and bone loss adjacent …