120 research outputs found

    X-ray of the rulers of the city of Elche

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    El objetivo de este Trabajo de Fin de Grado, es conocer por quién está gobernada la ciudad de Elche. Se han generado unos perfiles biográficos, que han sido creados a los concejales de Elche, y que han sido extraídos como consecuencia de haber realizado unas entrevistas en profundidad a cada uno de ellos. De este modo, sus vidas quedan registradas y se puede ver con claridad que personas rigen la ciudad de Elche. Pero, en este caso, solamente se tomará en cuenta a los concejales masculinos, con la intención de que exista otro trabajo complementario para definir el perfil de las concejalas de Elche. Pero para verlo de una manera más ilustrativa, las biografías se compararán las unas con las otras, exponiendo semblanzas y diferencias. Este paso se hará con el objetivo de identificar y analizar mejor cada uno de los perfiles que se han podido extraer de algunos de los concejales. Seguidamente, tras haber realizado la comparativa de las biografías de los concejales, se extraerán las conclusiones finales. Lo que en la comparativa inicial se mostrará de la forma más objetiva posible, con el fin de mostrar la realidad sin que sea alterada, en la parte final, en las conclusiones, se extraerán y mostrarán los resultados para determinar, así, si la ciudad de Elche está regida por unos perfiles competentes, o si, por el contrario, muestran deficiencias.The objective of this Final Degree Project is to know by whom the city of Elche is governed. Some biographical profiles have been generated, which have been created for the councilors of Elche, and which have been extracted as a resulto of having carried out in-depth interviews which each one of them. In this way, their lives are recorded and it can be clearly seen that people rule the city of Elche. But, in this case, only male councilors Will be taken into account, with the intention that there be other complementary work to define the profile of the councilwomen of Elche. But to see it in a more illustrative way, the biographies will be compared with each other, exposing resemblances and differences. This step Will be done whit the aim of better identifying and analyzing each of the profiles that have been extracted from some of the councillors. Next, after having made the comparison of the biographies of the councillors, the final conclusions will be drawn. What in the initial comparison will be shown in the most objective way possible, in order to show reality without being altered, in the final part, in the conclusions, the results will be extracted and shown to determinate if the city of Elche is governed by competent profiles, or if, on the conuntrary, they show deficiencies

    The loss of the inducible Aspergillus carbonarius MFS transporter MfsA leads to ochratoxin A overproduction

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    Ochratoxin A (OTA), a nephrotoxic compound produced by certain Aspergillus and Penicillium species, is one of the most abundant mycotoxins in food commodities. Aspergillus carbonarius is the main source of OTA in wine, grape juice and dried vine fruits. Although many studies have focused on OTA production by A. carbonarius, little is known about the genes related to OTA production and transport. We have found a transporter that belongs to the major facilitator superfamily (MfsA) which is highly expressed with a 102-fold induction in an ochratoxigenic A. carbonarius strain compared to a low OTA producer strain. The encoding mfsA gene shows similarity to the multidrug efflux transporter flu1 from Candida albicans. A high number of putative transcription factor binding sites involved in the response to stress were identified within the promoter of mfsA. Phenotypical analysis of δ. mfsA deletion mutants revealed that the loss of mfsA leads to a slight growth reduction and increased OTA production. We therefore hypothesize that MfsA could be a stress response transporter whose disruption could cause an increase in oxidative stress together with a stimulation of mycotoxin production. •A. carbonarius mfsA expression is induced over 100 fold in an OTA producing strain.•mfsA gene has been cloned and sequenced.•An A. carbonarius δmfsA null mutant has been obtained by ATMT.•The δmfsA null mutants produce more OTA than the parental strain.•The expression of mfsA is up regulated by hydrogen peroxide.A. Crespo-Sempere was recipient of a FPI fellowship from the Spanish Government. This research was supported by grants AGL2005-00707 and AGL2008-04828-C03-02 from the Spanish Government.Peer Reviewe

    Characterization and disruption of the cipC gene in the ochratoxigenic fungus Aspergillus carbonarius

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    Aspergillus carbonarius is considered the most important ochratoxin A (OTA) producing fungi among those causing OTA contamination in grapes and grape-derived products. CipC is a small protein with unknown function that was previously found to be highly up-regulated in an OTA producer strain of A. carbonarius in comparison to a non OTA producer strain. In this study, cipC was characterized and disrupted via Agrobacterium tumefaciens-mediated transformation in an ochratoxigenic A. carbonarius strain in order to study whether this gene has a role in OTA production. Sequence analysis indicated that the promoter region of cipC contains putative binding sites for transcription factors that regulate the utilization of nutrients, the stress response and detoxification processes, all factors that can influence mycotoxin biosynthesis. Although the {increment}. cipC mutant grew similarly to the wild type strain, the null mutant showed a much higher OTA production. Moreover, when A. carbonarius was grown under the oxidative stress conditions imposed by the presence of hydrogen peroxide, cipC gene expression was up-regulated. These results indicate that cipC is not directly involved in OTA biosynthesis, but sequence analysis of the A. carbonarius cipC gene promoter and the phenotype of the δ cipC disrupted mutant suggests that CipC could be a stress response protein that would be up-regulated concomitantly with OTA production. © 2013 Elsevier Ltd.A. Crespo-Sempere was recipient of a FPI fellowship from the Spanish Government. This research was supported by grants AGL2005-00707 and AGL2008-04828-C03-02 from the Spanish Government.Peer Reviewe

    Development of a green fluorescent tagged strain of Aspergillus carbonarius to monitor fungal colonization in grapes

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    An enhanced green fluorescent protein has been used to tag an OTA-producing strain of Aspergillus carbonarius (W04-40) isolated from naturally infected grape berries. Transformation of the fungus was mediated by Agrobacterium tumefaciens. The most efficient transformation occurred when the co-cultivation was done with 104 conidia due to higher frequency of resistance colonies (894 per 104 conidia) and lower background obtained. To confirm the presence of the hph gene in hygromycin resistant colonies, 20 putative transformants were screened by PCR analysis. The hph gene was identified in all the transformants. Variation on the expression levels of the eGFP was detected among the transformants and 50% of them appeared bright green fluorescent under the microscope. Microscopic analysis of all the bright fluorescent transformants revealed homogeneity of the fluorescent signal, which was clearly visible in the hyphae as well as in the conidia. eGFP expression in A. carbonarius was shown to be stable in all transformants. Confocal Laser scanning microscopy images of grape berries infected with the eGFP transformant demonstrated fungal penetration into the berry tissues. OTA production was importantly increased in the eGFP transformant in comparison with the wild type strain and pathogenicity on grape berries was slightly decreased after four days of inoculation. However, no differences in virulence were found after seven days of inoculation, thus allowing utilization of this eGFP mutant for in situ analysis of A. carbonarius infection of grape berries. To our knowledge, this is the first report describing the construction of a GFP-tagged strain belonging to Aspergillus section Nigri for monitoring Aspergillus rot on grape berries.This research was supported by AGL2005-00707/ALI and AGL2008-04828-C03-02 grants from the Spanish Government.Peer Reviewe

    Effects of temperature, water activity and incubation time on fungal growth and aflatoxin B1 production by toxinogenic Aspergillus flavus isolates on sorghum seeds

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    Sorghum, which is consumed in Tunisia as human food, suffers from severe colonization by several toxigenic fungi and contamination by mycotoxins. The Tunisian climate is characterized by high temperature and humidity that stimulates mold proliferation and mycotoxin accumulation in foodstuffs. This study investigated the effects of temperature (15, 25 and 37 ◦C), water activity (aw, between 0.85 and 0.99) and incubation time (7, 14, 21 and 28 d) on fungal growth and aflatoxin B1 (AFB1) production by three Aspergillus flavus isolates (8, 10 and 14) inoculated on sorghum grains. The Baranyi model was applied to identify the limits of growth and mycotoxin production. Maximum diameter growth rates were observed at 0.99 aw at 37 ◦C for two of the isolates. The minimum aw needed for mycelial growth was 0.91 at 25 and 37 ◦C. At 15 ◦C, only isolate 8 grew at 0.99 aw. Aflatoxin B1 accumulation could be avoided by storing sorghum at low water activity levels (≤0.91 aw). Aflatoxin production was not observed at 15 ◦C. This is the first work on the effects of water activity and temperature on A. flavus growth and AFB1 production by A. flavus isolates on sorghum grains.We thank M. Prim for her encouragement and technicalassistance. The authors are grateful to the European Union(MYCORED KBBE-2007-2-5-05 project) and Tunisian Govern-ment for financial support
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