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1.
Appl Neuropsychol Child ; : 1-13, 2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36441665

RESUMO

This study assessed the quantitative and qualitative performance of Lebanese-speaking children on verbal fluency (VF) tasks and investigated the effects of sociodemographic characteristics. This study included 219 Lebanese children aged between 5 and 12 years and 11 months, whose native language is Lebanese-Arabic. Semantic and letter VF tasks were assessed using a range of categories and letters. Switching and clustering strategies were analyzed for 177 Lebanese children. The number of words produced presented a significant increase with age (p < .004) in semantic (SVF), while in letter (LVF), the differences were significant between extreme age groups. Females generated more words in the clothes (p = .003) and household items (p = .002) categories. The total number of switches and clusters showed a significantly increasing pattern with age (p < .05). The number of switches was higher for participants with high maternal (p < .001) and paternal (p < .013) educational levels. Regression analyses showed that the total number of switches and clusters, and the mean cluster size had a significant effect on SVF performance (p < .001). The current study generated preliminary norms for VF tasks for Lebanese-speaking children. The results of the current study have an important contribution to neuropsychology research and clinical practice.

2.
Toxins (Basel) ; 14(4)2022 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-35448848

RESUMO

In malt production, steeping and germination steps offer favorable environmental conditions for fungal proliferation when barley is already contaminated by Fusarium species, T-2 toxin producers. However, the use of G. candidum as a biocontrol agent can prevent this proliferation. Indeed, in previous work, a correlation between phenyllactic acid (PLA) production by G. candidum and the reduction in Fusarium sporotrichioides and F. langsethiae growth and T-2 toxin concentration was demonstrated. In the present study, to improve the efficiency of G. candidum, the effects of the inoculum concentration and the inoculation method of G. candidum on PLA and T-2 toxin concentrations were evaluated. First, co-culture experiments with Fusarium species and G. candidum were conducted in a liquid synthetic medium. The results showed that inoculation of G. candidum in the freeze-dried form at 0.4 g/L allowed the production of PLA from the second day of incubation associated with a reduction in T-2 toxin concentration of 82% and 69% produced by F. sporotrichioides and F. langsethiae, respectively. Moreover, the activated form of G. candidum at 0.4 g/L enhanced PLA concentration leading to better T-2 toxin reduction. Second, experiments were conducted on artificially infected barley kernels with both Fusarium species under conditions mimicking the malting step. As for co-culture experiments, the use of the activated form of G. candidum was established as the best condition for T-2 toxin concentration reduction for a 3 day malting period.


Assuntos
Fusarium , Hordeum , Toxina T-2 , Geotrichum , Hordeum/microbiologia , Poliésteres
3.
Toxins (Basel) ; 12(4)2020 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-32224845

RESUMO

Fusariumsporotrichioides and F. langsethiae are present in barley crops. Their toxic metabolites, mainly T-2 toxin, affect the quality and safety of raw material and final products such as beer. Therefore, it is crucial to reduce Fusarium spp. proliferation and T-2 toxin contamination during the brewing process. The addition of Geotrichum candidum has been previously demonstrated to reduce the proliferation of Fusarium spp. and the production of toxic metabolites, but the mechanism of action is still not known. Thus, this study focuses on the elucidation of the interaction mechanism between G.candidum and Fusarium spp. in order to improve this bioprocess. First, over a period of 168 h, the co-culture kinetics showed an almost 90% reduction in T-2 toxin concentration, starting at 24 h. Second, sequential cultures lead to a reduction in Fusarium growth and T-2 toxin concentration. Simultaneously, it was demonstrated that G. candidum produces phenyllactic acid (PLA) at the early stages of growth, which could potentially be responsible for the reduction in Fusarium growth and T-2 toxin concentration. To prove the PLA effect, F. sporotrichioides and F.langsethiae were cultivated in PLA supplemented medium. The expected results were achieved with 0.3 g/L of PLA. These promising results contribute to a better understanding of the bioprocess, allowing its optimization at an up-scaled industrial level.


Assuntos
Grão Comestível/microbiologia , Microbiologia de Alimentos , Fusarium/metabolismo , Geotrichum/metabolismo , Hordeum/microbiologia , Lactatos/metabolismo , Controle Biológico de Vetores , Toxina T-2/metabolismo , Cerveja/microbiologia , Regulação para Baixo , Fermentação , Fusarium/crescimento & desenvolvimento , Cinética
4.
Antioxidants (Basel) ; 6(3)2017 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-28698493

RESUMO

This study is intended to prevent ochratoxin A (OTA) production by Aspergillus carbonarius S402 using essential oils (EOs) and total phenolic compounds extracted from plants and herbs. The EOs used in this study are the following: bay leaves, cumin, fenugreek, melissa, mint, and sage. As for the phenolic compounds, they were extracted from bay leaves, cumin, fenugreek, melissa, mint, sage, anise, chamomile, fennel, rosemary, and thyme. The experiments were conducted on Synthetic Grape Medium (SGM) medium at 28 °C for 4 days. OTA was extracted from the medium with methanol and quantified using HPLC (High Performance Liquid Chromatography). Results showed that EOs had a greater impact than the total phenolic extracts on the OTA production. Reduction levels ranged between 25% (sage) and 80% (melissa) for the EOs at 5 µL mL-1, and 13% (thyme) and 69% (mint) for the phenolic extracts. Although they did not affect the growth of A. carbonarius, total phenolic extracts and EOs were capable of partially reducing OTA production. Reduction levels depended on the nature of the plants and the concentration of the EOs. Reducing OTA with natural extracts could be a solution to prevent OTA production without altering the fungal growth, thus preserving the natural microbial balance.

5.
Toxins (Basel) ; 9(7)2017 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-28708102

RESUMO

Ochratoxin A (OTA) is one of the most important mycotoxins, and contaminates several agricultural products, particularly cereals, grapes, maize, barley, spices and coffee. The aim of this project was to reduce the levels of OTA by supplementing the artificially contaminated solutions with seven strains of actinobacteria (AT10, AT8, SN7, MS1, ML5, G10 and PT1) in order to evaluate their capacity for binding and metabolizing the OTA, as well as their ability to reduce the expression of the genes responsible for its production in A. carbonarius. In the first part of this study, we evaluated the capacity of Streptomyces strains for binding OTA on their surfaces after 0, 30 and 60 min of incubation with PBS solution supplemented with OTA. In the second part, we tested the ability of these strains, as well as their supernatants, to detoxify the ISP2 medium. Finally, we studied the effect of the Streptomyces cocultured with Aspergillus carbonarius on the expression of OTA biosynthesis genes. Results showed that, among the strains co-cultured with A. carbonarius, the strain G10 was able to reduce the expression of acpks, acOTApks, acOTAnrps and vea genes, thus reducing OTA from solid PDA medium to 13.50% of reduction. This strain was remarkably able to detoxify and bind OTA up to 47.07%. Strain AT8 was stronger in detoxifying OTA (52.61%), but had no significant effect on the studied gene expression.


Assuntos
Actinobacteria/química , Actinobacteria/metabolismo , Ocratoxinas/química , Ocratoxinas/metabolismo , Actinobacteria/isolamento & purificação , Aspergillus/genética , Aspergillus/crescimento & desenvolvimento , Biodegradação Ambiental , Parede Celular/química , Contaminação de Alimentos/prevenção & controle , Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Microbiologia do Solo , Streptomyces/química
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