Desempenho de novilhos em pastagem de braquiária decumbens permanente e após soja.

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Integração agricultura/pecuária.

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Parâmetros microbiológicos como indicadores da qualidade do solo sob sistemas integrados de produção agropecuária.

No presente estudo, foram avaliadas as alterações nos teores de carbono da biomassa microbiana (C microbiano) e índices derivados, num Latossolo Vermelho Distroférrico típico, em Dourados-MS. As avaliações foram realizadas no estádio inicial de maturação das culturas nas safras de verão 2000/2001, inverno de 2001, verão 2001/2002, inverno de 2002, verão 2002/2003 e inverno 2003, em sistemas intensivos de produção, contemplando a agricultura, a pecuária e a agropecuária integradabitstream/item/38775/1/BP200420.pd

Evaluation of different strains of Saccharomyces cerevisiae for ethanol production from high-amylopectin BRS AG rice (Oryza sativa L.)

Ethanol is the main biofuel produced by fermentation route and the search for new feedstocks to produce fuel ethanol is still a great challenge. This work aims to compare the ethanol production from a new irrigated rice cultivar BRS AG to the conventional cultivar BRS PAMPA applied in Brazil. Six different commercial strains of Saccharomyces cerevisiae (BG-1, CAT-1, FT-858, JP-1, PE-2, and SA-1) were applied in fermentation reactions. Fermentations performed with BRS PAMPA rice revealed that the highest yields were achieved with strain SA-1, corresponding to 93.0% of the theoretical maximum and final ethanol concentration of 58.92 g L−1, and with CAT-1, a yield of 92.7% and final ethanol concentration of 58.93 g L−1. For the fermentations with BRS AG rice, the highest yields were obtained with strain FT-858, exhibiting a 89.6% yield and final ethanol concentration of 62.45 g L−1, and with CAT-1, 87.9% yield and final ethanol concentration of 61.25 g L−1 were achieved. The most appropriate microorganism for ethanol production using BRS PAMPA rice and BRS AG rice was CAT-1. Comparatively, the ethanol yield and productivity using BRS AG were higher than those observed for BRS PAMPA for all strains, except for PE-2 and SA-1 that led to very similar results. The experimental results showed that the giant rice BRS AG is an excellent feedstock for fuel ethanol production in lowland fields

High molecular weight polystyrene particles by cationic miniemulsion polymerization catalyzed by an iron-containing imidazolium-based ionic liquid

Cationic styrene polymerizations in aqueous media were conducted using the miniemulsion polymerization technique with the ionic liquid 1-N-butyl-3-N-methylimidazolium heptachloro diferrate (BMI.Fe2Cl7) as catalyst, hexadecyltrimethylammonium bromide (CTAB) as surfactant and hexadecane as costabilizer. The ionic liquid was effective to initiate styrene miniemulsion polymerization at a BMI.Fe2Cl7:styrene molar ratios as low as 1:1000. Increasing the reaction temperature from 70 °C to 90 °C led to an increase in both, conversion and molecular weight. And polystyrene with much higher molecular weight (viscosity average molecular weights of up to 2231 kDa) than those usually obtained in cationic polymerizations was produced. Furthermore, while particle sizes remained almost constant around 150 nm during polymerizations, an almost linear increase of conversion with reaction time was observed. In addition, molecular weight increased steadily with conversion approaching the behavior of living cationic polymerization. Please click Additional Files below to see the full abstrac

Bioconversion of glycerol into lactic acid by a new bacterial strain from the Brazilian cerrado soil

A lactic-acid-producing strain was isolated from the Brazilian Cerrado soil (Brazilian savanna). Glycerol, a byproduct of the biodiesel industry, can be converted into various chemical intermediates of industrial value by biotechnological routes. Klebsiella pneumoniae can metabolize glycerol in environments with or without oxygen and bioconvert it into several chemicals with high value-added, such as lactic acid, 3-hydroxypropionic acid and 1,3 propanediol. The wild-type bacterial strain (2GPP) isolated from a soil sample from the Brazilian Cerrado was determined to be a K. pneumoniae complex that was capable of successfully metabolizing glycerol. Fermentations were performed with different temperatures, pH, and inoculum concentrations to evaluate the best lactic acid production. At first, 1,3-propanediol and L-(+)-lactic acid were produced in mini reactors. A lactic acid production of 3.8 g·L −1 and a decrease in 1,3-propanediol output were observed. Thus, by adjusting process variables such as pH and temperature during fermentation, it was possible to maximize the production of lactic acid and decrease the formation of 1,3-propanediol by utilizing experimental design strategies

Solos.

Amostragem; Critérios para a divisão da área de amostragem; Numero de amostras simples ou subamostras; Profundidade de coleta de subamostras; Composição da amostra; Material para a amostragem; época, freqüência e algumas recomendações gerais para amostragem; Acondicionamento e identificação da amostra; Registro e preparo da amostra; Secagem; Moagem, peneiragem e armazenagem