RESUMO
Marine environments are a reservoir of relevant information on dangerous contaminants such as hydrocarbons, as well as microbial communities with probable degradation skills. However, to access microbial diversity, it is necessary to obtain high-quality DNA. An inexpensive, reliable, and effective metagenomic DNA (mgDNA) extraction protocol from marine sediments contaminated with petroleum hydrocarbons was established in this study from modifications to Zhou's protocol. The optimization included pretreatment of sediment with saline solutions for the removal of contaminants, a second precipitation and enzymatic degradation of RNA, followed by purification of mgDNA extracted by electroelution. The results obtained indicated that the modifications applied to 12 sediments with total petroleum hydrocarbon (TPH) concentrations from 22.6-174.3 (µg/g dry sediment) yielded 20.3-321.3 ng/µL mgDNA with A260/A280 and A260/A230 ratios of 1.75 ± 0.08 and 1.19 ± 0.22, respectively. The 16S rRNA amplification confirmed the purity of the mgDNA. The suitability of this mgDNA extraction protocol lies in the fact that all chemical solutions utilized are common in all molecular biology laboratories, and the use of dialysis membrane does not require any sophisticated or expensive equipment, only an electrophoretic chamber.
Assuntos
Sedimentos Geológicos/microbiologia , Metagenoma , Poluição por Petróleo/efeitos adversos , Água do Mar/microbiologia , Fracionamento Químico/métodos , Sedimentos Geológicos/química , Hidrocarbonetos/química , RNA Ribossômico 16S/química , RNA Ribossômico 16S/normas , Água do Mar/químicaRESUMO
During 2004 and 2005, a powdery mildew was observed in tomato (Lycopersicon esculentum Mill. cv. Rio Grande) fields in several states in Venezuela. Symptoms included development of patches of dense white mycelium, predominantly on the upper leaf surface. Leaves in the middle and lower canopies were the most affected. Similar symptoms sometimes were observed on stems. The foliage of infected plants turned yellow and showed necrosis followed by desiccation and rapid defoliation. Microscopic examination revealed the presence of typical structures of the Oidium genus. Hyphae were hyaline and septate. Conidiophores were unbranched, erect, measured 51 to 108 (80) µm, and consisted of 3 or 4 cells. Conidia were hyaline, ellipsoidal to ovoidal, and measured 16 to 43 (30) × 12 to 22 (16) µm. Conidia were produced singly, without fibrosin bodies. Conidial polar germination was common. Appressoria were lobed. The sexual stage was not found. The fungus was identified as Oidium neolycopersici, recently recognized as a distinct species (1,2). Conidia from infected tomato leaves were shaken onto leaves of 10 plants of L. esculentum and L. pimpinellifolium (Jusl.) Mill. and five plants of a weed (Physalis peruviana L.). Noninoculated plants served as a control. Symptoms that developed on all inoculated plants were similar to those of plants naturally infected. Within 7 to 8 days, symptoms in L. esculentum consisted of small colonies that quickly covered large portions of foliar tissue. L. pimpinellifolium showed small and localized symptoms after 10 days and P. peruviana showed symptoms after 15 days. To our knowledge, this is the first report of O. neolycopersici in Venezuela. References: (1) H. Jones et al. Mol. Plant Pathol. 2:303, 2001. (2) L. Kiss et al. Mycol. Res. 105:684, 2001.
RESUMO
Se analizan la problemática de la producción arrocera de Venezuela, y se hace hincapié sobre la reducida área cultivada con este cereal, la limitación del riego y los bajos en comparación con otros países. La potencialidad de producción es alta, debido a las condiciones climáticas, recursos hidrológicos y tierras, aptas para este cultivo. Las posibilidades para la expanción del mismo son muy buenas comparados con las del maíz y trigo, cuya oferta depende y dependerá de las importaciones. Se enumeran diversas vías para incrementar la demanda por arroz, que es muy baja comparada con otros países tropicales de Latinoamérica. Este incremento se debe buscar a través de ofertas de arroz a precios populares, variando el grado de beneficio y porcentaje de granos partidos. Además se propone impulsar los usos industriales en la producción de pastas, pan, harina de maíz, un sucedáneo de leche (lactovisoy), edulcorantes, aceite vegetal y en alimentos para animales. La seguridad alimentaria de Venezuela depende en gran parte de un incremento de la producción y del consumo de este cereal
Assuntos
Humanos , Grão Comestível/economia , Dieta , Oryza/economia , Oryza/crescimento & desenvolvimento , VenezuelaRESUMO
The main ecophysiologic, agronomic and economic feature of legume plants is the development of tubercles and nodules in their apical system. Nodule formation occurs in most legume species provided a compatible type of Rhizobium bacteria is present in the soil. Nitrogen fixation in nodules renders these plants independent of nitrogen fertilizers, the most expensive of all goods in modern cereal agriculture. Considering that soils may get enriched in nitrogen through fixation in nodules and the decomposition of foliage when the aerial parts of legume plants are used as green fertilizers, only through the inclusion of legume crops within planned harvest schemes, it would be possible to achieve success in large scale production strategies. Legume crops are extensively produced in temperate climates areas in which, in addition to their use in animal nutrition, yields of 18 kg per person per year are obtained. In contrast, in the Third World countries located in tropical areas, legume production is scarce, with annual yields of 9 kg per person per year. Currently, it is proposed that the energy and protein intake should match that of the developed countries 40 years ago (i.e. 3000 Kcal and 70 g protein per day); for this, it would be necessary to have an average availability of 60 g of legume seeds per person per day. Therefore, the production of legume seeds should be increased. In addition, research aimed to study and exploit the agronomic potential of this rich botanical family should be strengthened through the formation of interdisciplinary groups.
Assuntos
Agricultura , Fabaceae , Fenômenos Fisiológicos da Nutrição , Plantas Medicinais , Humanos , Necessidades NutricionaisRESUMO
There were made four nutrition experiments using pork in growing process, with an approximate weight of 14.2 kilograms. In each experiment, it was made a substitution in equals parts of corn flour and soy flour for raw Canavalia flour or processed through alkaline storage, autoclaved or extrusion. In the first three experiments, the substitution level of raw Canavalia (RC), stored in alkaline environment (CAMA) or autoclave (CA) were: 0, 5, 10 and 15%. In the fourth one, the including levels of Canavalia Extruida were: 0, 7.5 and 15%. The raw Canavalia as the Extruida drastically reduced the pork's growth. The Canavalia flour autoclaved (121 degrees C/15 psi/90 min) substantially improved the animal answers, even though the growth in all the substitution levels were lower than the one observed in the original portion. The storage of the beans in alkaline environment, made possible better productive behavior in the animals, and it didn't observe differences (p < 0.01) to increase the witness weight, at the substitution level or 5%. The pork's answer to the Canavalia toxin was manifested in the first term, by a drastic reduction in the voluntary consumption of foods. As a whole, the results indicated that none of the methods used were effective to eliminate or to minimize the toxic effects in the raw Canavalia over the productive behavior of growing pork.
Assuntos
Ração Animal , Fabaceae , Farinha , Manipulação de Alimentos/métodos , Proteínas de Plantas , Plantas Medicinais , Suínos/crescimento & desenvolvimento , Toxinas Biológicas , Aminobutiratos/análise , Ração Animal/análise , Animais , Canavanina/análise , Concanavalina A/análise , Fabaceae/química , Conservação de Alimentos/métodos , Hemaglutinação , Temperatura Alta , Concentração de Íons de Hidrogênio , Lectinas/análise , Extratos Vegetais , Lectinas de Plantas , Plantas Tóxicas/química , Sementes/químicaRESUMO
A bioassay in broilers was carried out during a six-week period, to evaluate, as a protein source, the quality of fish silage produced by microbiological means and to compare it with that of fish flour and soybean flour. A total of 28 broilers of the Cross by Cross strain were used, sexed and assigned at random. Additionally, the fish silage was subjected to moisture (8.1%), ash (18.4%), protein (59.5%), fat (7.55%), carbohydrates (6.47%), and pH (4.2) determinations for its inclusion in the diets formulation. The results obtained did not permit establishment of significant differences between the weight increments presented by chicks fed with fish flour, and those fed with fish silage. Nevertheless, the food conversion index of the chicks consuming the diet prepared with fish silage proved to be better that the conversion index of the diet prepared with fish and soy flours. No lesions in the organs of the animals studied were observed, and the sensory trials indicated that chicks fed with the fish silage did not present differences with those commercially acquired.
Assuntos
Proteínas de Bactérias/análise , Produtos Pesqueiros , Silagem/análise , Criação de Animais Domésticos , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bioensaio , Peso Corporal , Galinhas , Proteínas Alimentares/análise , Alimentos Fortificados/análise , Valor Nutritivo , Aumento de PesoRESUMO
Se llevó a cabo un bioensayo de seis semanas, con pollos de engorde, para evaluar la calidad del ensilado de pescado producido por vía microbiana como fuente proteínica, y compararlo con harina de pescado y harina de soya. Se utilizaron, para el caso, 128 pollo sexados del cruce Cobb x Cobb, dispuestos en forma aleatoria. Adicionalmente, el ensilado de pescado se sometió a determinaciones de humedad (8.1%), cenizas (18.4%), proteínas (59.5%), grasas (7.55%), carbohidratos (6.47%), pH (4.2) a fin de efectuar su inclusión en la formulación de las dietas. Los resultados obtenidos no permitieron establecer diferencias significativas entre los incremento de peso desarrollados por las aves alimentadas con harina de pescado y los pollos alimentados con ensilado de pescado. Sin embargo, el índice de conversión de la aves que consumieron la dieta con ensilado de pescado resultó ser mejor que el índice de conversión de la dieta con harina de pescado y con harina de soya. No se observaron lesiones en los órganos de las aves sometidas a estudio, y las pruebas sensoriais indicaron que los pollos alimentados con ensilado de pescado no presentaban diferencias con los pollo adquiridos comercialmente
Assuntos
Animais , Produtos Pesqueiros , Proteínas de Bactérias/análise , Silagem/análise , Fenômenos Fisiológicos da Nutrição Animal , Bioensaio , Peso Corporal , Galinhas , Alimentos Fortificados/análise , Valor Nutritivo , Proteínas Alimentares/análise , Aumento de PesoRESUMO
The purpose of this study was the nutritional evaluation of proteins in fish silage. A biological test was conducted in chicks (broilers) to evaluate two levels of inclusion of fish silage (2.5% and 5%, respectively) in diets normally used for feeding them. Chicks were evaluated in weight gain, food consumption, and feeding conversion index. Finally, flavor and acceptability tests of meat from broilers fed the experimental diet were conducted. Results of the biological assay indicated that the best biological response was that of the animals fed the 5% fish silage diet. Sensory tests revealed that the meat of chicks fed the experimental diets had favorable acceptance by the consumers.
Assuntos
Galinhas , Produtos Pesqueiros , Alimentos Formulados , Silagem , Aumento de Peso , Animais , Galinhas/crescimento & desenvolvimento , Tecnologia de Alimentos , Valor NutritivoRESUMO
Fish silage was prepared from some fish species of the shrimp by-catch caught in Golfo Triste, Carabobo, Venezuela. Fish were ground until a particle size that would guarantee the liquefaction process was achieved. The process was accelerated by the incorporation of a 3.5% w/w acid mixture, formed by diluted sulfuric acid (1:3) and concentrated formic acid, in a proportion of 1:4. The silage process occurred spontaneously at room temperature during 17 days. Chemical, physical and microbiological tests were conducted in order to characterize both the raw material and the final product. The raw material used had adequate levels of freshness, so that it was suitable for use, thus producing a first-grade silage. A first biological evaluation was carried out in rats in order to estimate the protein quality of the silage by means of certain biological parameters such as PER, NPR and apparent digestibility percentage of the protein. The results of the first experimental period demonstrated that the fish silage protein was of optimal quality, since the biological response in rats was similar to that of the control group fed the casein diet.
Assuntos
Produtos Pesqueiros , Manipulação de Alimentos , Silagem/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Peso Corporal , Proteínas Alimentares/análise , Conservação de Alimentos , Tecnologia de Alimentos , Formiatos/administração & dosagem , Valor Nutritivo , Ratos , Ácidos Sulfúricos/administração & dosagem , Aumento de PesoRESUMO
A new method of preserving eggs at room temperature is discussed. The method consists in the "plastification" in situ of the shell, using a liquid synthetic polyvinyl chloride acetate plastic. The plastified eggs and controls were stored under laboratory conditions at 22 degrees C, and the following variables were studied in relation to time: pH of the thick and fluid white, and of the yolk, loss of weight, diameter, yolk index and Haugh units. The results indicated that this new method preserves edible eggs for periods longer than 135 days.