Search results for "Fungi Imperfecti"
showing 10 items of 78 documents
SCAR-based real time PCR to identify a biocontrol strain (T1) of Trichoderma atroviride and study its population dynamics in soils.
2006
Strains of Trichoderma spp. are known for their antagonistic properties against plant pathogens, some are already on the market, others are under development. In order to launch a strain on the market its perfect identification at the species and strain levels is needed. The aim of this study is to (i) design a SCAR marker for specific identification of strain T1 of Trichoderma atroviride and (ii) monitor population dynamics of this strain in soil by real time PCR. A primer pair targeting a 141-bp fragment enabled specific detection of this strain without cross detection of autochthonous populations of Trichoderma in several field soils. In two soils, population dynamics assessed by real ti…
In vitro and in vivo anticryptococcal activities of a new pyrazolo-isothiazole derivative
2003
We investigated the activity of a pyrazolo-isothiazole derivative (G8) against Cryptococcus neoformans. A first screening test showed that G8 at 10 mg/L inhibited the growth of 14 of 15 clinical isolates tested. Killing experiments showed that fungicidal activity was achieved after 8 h of treatment with G8 at concentrations > or =10 mg/L. In a murine model of systemic cryptococcosis, G8 was effective at prolonging survival compared with the controls. Our data indicate that this new derivative has a potential therapeutic role in infections caused by C. neoformans.
Identification of Colletotrichum species responsible for anthracnose of strawberry based on the internal transcribed spacers of the ribosomal region.
2000
In recent years, different molecular techniques have led to an important progress in the characterisation of Colletotrichum species, but there are no available methods which permit the easy identification of Colletotrichum strains and their assignation to classical species. In the present work, the restriction patterns generated from the region spanning the internal transcribed spacers (ITS1 and ITS2) and the 5.8S rRNA gene, were used to identify a total of 80 strains of Colletotrichum, the majority of them isolated from strawberry. One of the most interesting results derived from this study was the easy and reliable distinction, using the endonuclease MvnI, between Colletotrichum fragariae…
Digestion of DNA regions to discriminate ochratoxigenic and non-ochratoxigenic strains in the Aspergillus niger aggregate
2005
Abstract Aspergillus strains belonging to the Aspergillus niger aggregate, either isolated from Italian grapes or received from public collections, were analysed in order to discriminate between the ochratoxin A (OTA) producing and the non-producing strains by means of the analysis of Internal Transcribed Spacers (ITS), Intergenic Spacers (IGS) and of a β-tubulin gene portion. A. niger and Aspergillus awamori were identified observing the macro- and microscopic features of the colonies and the strains ochratoxigenicity was evaluated through Thin Layer Chromatography and/or High Performance Liquid Chromatography. PCR amplification of ITS, IGS and β-tubulin gene portion produced 600, 440 and …
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…
Genes differentially expressed by Aspergillus carbonarius strains under ochratoxin A producing conditions
2010
Aspergillus carbonarius is an important ochratoxin A (OTA)-producing fungus that is responsible for toxin contamination of grapes and wine, coffee and cocoa. A suppression subtractive hybridization (SSH) approach was performed with two strains of A. carbonarius, antagonistic in their OTA-production ability, to identify genes whose expression is linked with the ability to produce OTA. BlastX analysis identified 109 differentially-expressed sequences putatively involved in the production of OTA, with significant similarities (Evalue < 10− 5) to sequences deposited in the NCBI non-redundant protein database. Of the 109 ESTs, 26% were involved in regulation processes, 15% corresponded to hypoth…
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 …
A new species of Pythium isolated from a vineyard in France.
2006
Pythium apiculatum sp. nov. is a new oomycete characterized by the presence of both ornamented and smooth-walled oogonia. The ornamentations are blunt, and at times, bent. The oomycete was isolated from soil samples taken in a vineyard in the Burgundian region of France. Morphologically, it resembles some species having ornamented oogonia like Pythium radiosum, Pythium echinulatum, and resembles, also the species having smooth-walled oogonia like Pythium hypogynum and Pythium acrogynum. However, the oomycete has its own distinguishing characteristics which, when combined with molecular features, enables us to describe it as a new species. The taxonomic description of this new oomycete, its …
Differentiation of Penicillium griseofulvum Dierckx isolates by enzyme assays and by patulin and griseofulvin analyses
1990
The production of patulin and griseofulvin by 49 different isolates of Penicillium griseofulvum Dierckx was analyzed by high-performance liquid chromatography. Eleven isolates were obtained from pistachio nuts, 37 were obtained from wheat seeds, and 1 was obtained from the American Type Culture Collection. Activities of 19 enzymes were also assayed by the API ZYM system. From these results it may be deduced that there are two different groups among the strains tested which cannot be distinguished by morphological and cultural characteristics. One group of isolates did not produce detectable amounts of patulin and griseofulvin when grown in sucrose-yeast extract and Wickerham media, while en…
Penicillium auxotrophic mutants can be detected by suing xanthene dyes
1987
Auxotrophic mutants ofPenicillium spp. have been directly isolated after mutagenic treatment from agar plates containing Xanthene dyes. They grow as characteristic small colored colonies. Some strains were tested and they showed a differential response depending on the Xanthene dye used.