ABSTRACT
Mycotoxins may be present in nuts, coffee, cereals, and grapes, among other products. Increasing concerns about human health and environmental protection have driven the application of biological control techniques that can inhibit fungal contaminants. In this study, the growth inhibition of the ochratoxigenic fungus Aspergillus carbonarius Ac 162 was evaluated using 5 lactic acid bacteria (LAB). The LAB studied were Lactobacillus plantarum MZ801739 (J), Lactobacillus plantarum MZ809351 (31) and Lactobacillus plantarum MZ809350 (34), isolated in the Ivory Coast, and Lactobacillus plantarum MN982928 (3) and Leuconostoc citreum MZ801735 (23), isolated in Mexico. J, 31, 34, 3 and 23 are the internal strain codes from our laboratory. LAB were cultivated in De Man, Rogosa and Sharpe (MRS) broth, and different polyols (glycerol, mannitol, sorbitol, and xylitol) were added to the culture broth to stimulate the production of antifungal compounds. The fungal inhibition studies were performed using the poisoned food technique. The highest inhibition of A. carbonarius growth was obtained by cultivating L. plantarum MZ809351 in the presence of xylitol and glycerol. Under these conditions, 1 L of the L. plantarum MZ809351 cultures were used to identify antifungal compounds. The compounds were concentrated by solid-phase extraction and then characterized by GC-MS. In addition to 9-octadecenoic acid, 3 diketopiperazines or cyclic dipeptides were identified, including cyclo (Leu-Leu), cyclo (Pro-Gly) and cyclo (Val-Phe), which were compounds related to microbial antifungal activities. Xylitol and glycerol induced the production of these antifungal compounds against A. carbonarius Ac 162. On the other hand, adding xylitol and glycerol to the MRS broth reduced the Ochratoxin A (OTA) content to 56.8 and 54.7%, respectively. This study shows the potential for using L. plantarum MZ809351 as a biocontrol agent to prevent the growth of A. carbonarius and reduce the production of OTA in foods.
Subject(s)
Lactobacillus plantarum , Mycotoxins , Antifungal Agents/pharmacology , Humans , PolymersABSTRACT
We investigated thermal properties of the epoxy-based composites with the high loading fraction-up to f ≈ 45 vol %-of the randomly oriented electrically conductive graphene fillers and electrically insulating boron nitride fillers. It was found that both types of the composites revealed a distinctive thermal percolation threshold at the loading fraction fT > 20 vol %. The graphene loading required for achieving thermal percolation, fT, was substantially higher than the loading, fE, for electrical percolation. Graphene fillers outperformed boron nitride fillers in the thermal conductivity enhancement. It was established that thermal transport in composites with high filler loadings, f ≥ fT, is dominated by heat conduction via the network of percolating fillers. Unexpectedly, we determined that the thermal transport properties of the high loading composites were influenced strongly by the cross-plane thermal conductivity of the quasi-two-dimensional fillers. The obtained results shed light on the debated mechanism of the thermal percolation, and facilitate the development of the next generation of the efficient thermal interface materials for electronic applications.
ABSTRACT
El síndrome hipoplasia cartílago cabello también conocido como condrodisplasia Metafisiaria tipo Mc Kusickes una enfermedad autosómica recesiva que presenta múltiples manifestaciones fenotípicas, tales como talla baja con miembros cortos, alteraciones osteocondrales, extremidades cortas, vello corporal y cabello fino y escaso, piernas relativamente cortas con arqueamiento de los fémures, manos cortas y uñas pequeñas, defectos variables en la inmunidad celular y predisposición a una variedad de neoplasias. El manejo médico de estos pacientes requiere un enfoque multidisciplinario con especialistas en hematología, genética, nutrición y estomatología pediátrica. Se reporta el caso de un paciente con este síndrome al cual fue rehabilitado en el servicio de Odontopediatría del Departamento de Estomatología del Hospital Infantil de México Federico Gómez.
Kusick type is an autosomal recessive disease, has multiple phenotypic manifestations such as hypoplastic hair, short stature, osteochondral abnormalities, short limbs, fine and sparse hair, thin body hair scares relatively short legs with bow femurs, short hands and nails small defects in cellular immunity variables and predisposition to a variety of neoplasm. Management of these patients requires a multidisciplinary approach with specialists in hematology, genetics nutrition and pediatric dentistry. This case report describes phonotypical manifestations of patient with this syndrome who received dental treatment in the Pediatric Dentistry Service at Hospital Infantile de Mexico Federico Gómez .
