1,221 research outputs found

    Thermophilic fungi to dominate aflatoxigenic/mycotoxigenic fungi on food under globalwarming

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    Certain filamentous fungi produce mycotoxins that contaminate food. Mycotoxin contamination of crops is highly influenced by environmental conditions and is already affected by global warming, where there is a succession of mycotoxigenic fungi towards those that have higher optimal growth temperatures. Aflatoxigenic fungi are at the highest limit of temperature although predicted increases in temperature are beyond that constraint. The present paper discusses what will succeed these fungi and represents the first such consideration. Aflatoxins are the most important mycotoxins and are common in tropical produce, much of which is exported to temperate regions. Hot countries may produce safer food under climate change because aflatoxigenic fungi will be inhibited. The same situation will occur in previously temperate regions where these fungi have recently appeared, although decades later. Existing thermotolerant and thermophilic fungi (TTF) will dominate, in contrast to the conventional mycotoxigenic fungi adapting or mutating, as it will be quicker. TTF produce a range of secondary metabolites, or potential mycotoxins and patulin which may become a new threat. In addition, Aspergillus fumigatus will appear more frequently, a serious human pathogen, because it is (a) thermotolerant and (b) present on crops: hence this is an even greater problem. An incubation temperature of 41 ºC needs employing forthwith to detect TTF. Finally, TTF in crops requires study because of the potential for diseases in humans and animals under climate change.This study was supported by the Portuguese Foundation for Science and Technology (FCT). It was under the scope of the strategic funding of the UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684) and the BioTecNorte operation (NORTE-01-0145-FEDER-000004), funded by the European Regional Development Fund through the Norte2020—Programa Operacional Regional do Norte

    Climate change affects fungal diseases of the important oil palm crop

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    Book of Abstracts of CEB Annual Meeting 2017[Excerpt]Palm oil is a very important commodity used in 40% of supermarket products, cooking, cosmetics, pharmaceuticals and increasingly, biodiesel. Eighty five percent of palm oil is produced in Malaysia and Indonesia. Also, palm oil production impacts the environment negatively and increases greenhouse gases (GHG). The crop is subjected to serious diseases, including those caused by fungi, which increase when oil palm (OP) are grown under sub-optimal conditions. Climate change is predicted to decrease the ability to produce disease-free OP after 30 and especially 80 years in Malaysia and Indonesia [1]. This affects negatively the sustainability of the palm oil industry, and increases pressure on destroying forests to further grow the cash crop. A limited number of areas gained more suitable climates for growing disease-free OP. [...]info:eu-repo/semantics/publishedVersio

    Fundamental Studies on the Physical Chemistry of Inorganic Ion Exchangers

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    How will climate change affect oil palm fungal diseases?

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    Palm oil is a very important commodity. It is added to numerous products and is a biofuel. However, oil palms (OP) are subjected to fungal diseases of which Fusarium wilt and Ganoderma rots are the most important. Considerations of how climate change (CC) affects tropical economic plants are limited and for OP are even fewer. The margin for adapting to higher temperatures and changing humidity is reduced in tropical OP. Land will become increasingly unsuitable for growing OP and the plants will become stressed allowing ingress of fungal diseases. New land will be increasingly suitable where the environmental conditions are less severe than in the tropics. Novel diseases may threaten the crop. Finally, the effect of the major consequences of CC on OP fungal diseases is considered herein with a view to establishing key hypotheses

    Zearalenone production and growth in drinking water inoculated with Fusarium graminearum

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    Production of the mycotoxin zearalenone (ZEN) was examined in drinking water inoculated with Fusarium graminearum. The strain employed was isolated from a US water distribution system. ZEN was purified with an immunoaffinity column and quantified by high-performance liquid chromatography (HPLC) with fluorescence detection. The extracellular yield of ZEN was 15.0 ng l−1. Visual growth was observed. Ergosterol was also indicative of growth and an average of 6.2 μg l−1 was obtained. Other compounds were also detected although remain unidentified. There is no equivalent information available. More work is required on metabolite expression in water as mycotoxins have consequences for human and animal health. The levels detected in this study were low. Water needs to be accepted as a potential source as it attracts high quality demands in terms of purity.Fundação para a Ciência e a Tecnologia (FCT

    Fusion Protein of the Paramyxovirus SV5: Destabilizing and Stabilizing Mutants of Fusion Activation

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    AbstractThe fusion (F) protein of the paramyxovirus SV5 strain W3A causes syncytium formation without coexpression of the SV5 hemagglutinin-neuraminidase (HN) glycoprotein, whereas the F protein of the SV5 strain WR requires coexpression of HN for fusion activity. SV5 strains W3A and WR differ by three amino acid residues at positions 22, 443, and 516. The W3A F protein residues P22, S443, and V516 were changed to amino acids found in the WR F protein (L22, P443, and A516, respectively). Three single-mutants, three double-mutants, and the triple-mutant were constructed, expressed, and assayed for fusion using three different assays. Mutant P22L did not cause fusion under physiological conditions, but fusion was activated at elevated temperatures. Compared with the W3A F protein, mutant S443P enhanced the fusion kinetics with a faster rate and greater extent, and had a lower activation temperature. Mutant V516A had little effect on F protein-mediated fusion. The double-mutant P22L,S443P was capable of causing fusion, suggesting that the two mutations have opposing effects on fusion activation. The WR F protein requires coexpression of HN to cause fusion at 37°C, and does not cause fusion at 37°C when coexpressed with influenza virus hemagglutinin (HA); however, at elevated temperatures coexpression of WR F protein with HA resulted in fusion activation. In the crystal structure of the core trimer of the SV5 F protein (Baker, K. A., Dutch, R. E., Lamb, R.A., and Jardetzky, T. S. (1999). Mol. Cell 3, 309–319), S443 is the last residue (with interpretable electron density) in an extended chain region and the temperature factor for S443 is high, suggesting conformational flexibility at this point. Thus, the presence of prolines at residues 22 and 443 may destabilize the F protein and thereby decrease the energy required to trigger the presumptive conformational change to the fusion-active state

    Excited electronic states of MnO4−:Challenges for wavefunction and density functional response theories

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    AbstractThe lowest excited electronic states of the permanganate ion MnO4− are calculated using a hierarchy of coupled cluster response approaches, as well as time-dependent density functional theory. It is shown that while full linear response coupled cluster with singles and doubles (or higher) performs well, that permanganate represents a stern test for approximate coupled cluster response models, and that problems can be traced to very large orbital relaxation effects. TD-DFT is reasonably robust although errors around 0.6eV are still observed. In order to further investigate the strong correlations prevalent in the electronic ground state large-scale RASSCF calculations were also performed. Again very large orbital relaxation in the correlated wavefunction is observed. Although the system can qualitatively be described by a single configuration, multi-reference diagnostic values show that care must be taken in this and similar metal complexes

    Alternative patulin pathway unproven

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    Letter to the Editor[Excerpt] We read with interest in your journal that Penicillium expansum strains S3, S31 and S87 ( Rharmitt et al., 2016) were considered negative for possession of the isoepoxydon dehydrogenase (idh) gene for patulin (PAT) production and positive for PAT production. This led to speculation that an alternative pathway was involved in patulin production. However, the authors did not provide the diode array (DA) UV spectra of the HPLC peaks assigned to PAT, which assist in confirming its identification. UV spectra could usefully be provided in papers when DA analysis has been performed especially for unusual results such as these: At least a statement to say whether the spectra were identical, or not, to the PAT standard is required. [...]FCT -Fundação para a Ciência e a Tecnologia(UID/BIO/04469/2013)info:eu-repo/semantics/publishedVersio
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