Degradabilidade ruminal do amido de silagem de milho, farelo de soja e sorgo grão, em bovinos da raça Nelore

Four Bos indicus (Nellore) ruminally-fistulated animals, averaging 36 months of age and 520 kg, were used in a randomized block design to study the ruminal degradability of starch in corn silage, soybean meal, and sorghum grain. The experimental diets consisted of two levels of concentrate (18 and 39%) plus corn silage. The concentrate ingredients used were soybean meal, cottonseed meal, corn grain, and sorghum grain. The degradation rate of sorghum grain increased 40.2% in diet 2 . The potential degradability of starch (PDS) was similar in the two diets. There was no difference between the two diets in the effective degradability of starch (EDS) in corn silage. There was a significant increase of 26.5% in the EDS of starch in sorghum grain with the increase of level of concentrate in the diet, and considering the lag time in the calculation. The starch level estimated in this study was lower than the values cited in the literature, probably due to different laboratory methods for determining the starch content in feedstuffs. Previous studies suggested using a minimum of 6 incubation intervals between 2 and 24 hours.

Estabilidade física de péletes protegidos por diferentes produtos impermeabilizantes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cassava bagasse as a dietary food product

Cassava bagasse, the solid residue of the starch industry, was studied as a potential ingredient in high-fibre dietary products. The bagasse contained 80% of starch, 11.5% fibre, 1.14% ash and 0.85% of protein, and it had a pH of 5.8. Glucose was the major sugar and the hemicellulose content was 22.31%. Microscopic analysis of the bagasse revealed a large number of starch granules inside the parenchyma cells and fibres, as well as outside the cells. The bagasse may be used in high-fibre products, and total or partial hydrolysis of its starch content might increase its commercial value.

Clonal relationship among invasive and non-invasive strains of enteroinvasive Escherichia coli serogroups

The genetic relatedness among 96 invasive Escherichia coli belonging to several serogroups and 13 non-invasive of several serotypes that share the same O antigen was investigated by multilocus enzyme electrophoresis analysis. The invasive strains were isolated in different parts of the world and most of them recovered from dysentery. Twenty-nine electrophoretic types were distinguished and the most invasive strains were found to belong to two major lineages. These results suggested that the invasive ability in these strains has evolved in divergent chromosomal backgrounds, presumably through the horizontal spread of plasmid-borne invasion genes. The maintenance of invasive phenotypes in separate lineages suggests that this ability confers a selective advantage to invasive strains. Copyright (C) 1999 Federation of European Microbiological Societies.

Control of amylase production and growth characteristics of Aspergillus ochraceus

The growth and the extracellular amylase production by Aspergillus ochraceus were studied in a stationary culture medium. Maximum growth rate of this fungus was found after 5 days of incubation at 30° C, but maximum amylase production was obtained after 2 days. The highest amylase production were attained with lactose, maltose, xylose and starch as carbon sources. The extracellular amylase production and mycelial growth were influenced by the concentration of starch. Other carbohydrates supported growth but did not induce amylase synthesis and glucose repressed it, indicating catabolite repression in this microorganism. The presence of both mechanisms of induction and repression suggests that at least these multiple forms of regulation are present in A. ochraceus. Of the nitrogen sources tested, casaminoacids, ammonium nitrate and sodium nitrate stimulated the highest yield of amylase. Optimal amylase production was obtained at pH 5.0, but enzyme activity was found only in the 4.0-6.0 pH range. These results were probably due to the inhibitory effect of NH 4 +-N in the culture medium.

Polissacarídeos biodegradáveis úteis para a preparação de sistemas de liberação controlada de fármacos. Parte 1: Quitosana

Due to an increasing interest, a vast number of biodegradable polymers have been obtained recently. Polymers naturally produced, such as cellulose, starch, chitosan and alginate, represent biodegradable materials, with low toxicity and low cost. Among polysaccharides, chitosan has been of great interest of the industrial and academic research, due to its special qualities of biodegradability and biocompatibility and, on the other hand, to the versatility of its use in several physical forms and products. A significant growth in the development of new dosage forms capable to deliver the drug in a controlled and targeted way has been observed in these last years. Such pharmaceutical forms search, mainly, the reduction of the dose administered and of the administration frequency, the reduction of adverse side effects and, consequently, a better patient compliance. The present paper describes the use of chitosan in pharmaceutical products, especially in drug controlled delivery systems.

Effect of benzylaminopurine (BAP) on clonal propagation rate of Curcuma longa L.

Curcuma longa L. is used in many countries for its flavor, and medicinal and cosmetic attributes, as well as for its peculiar starch characteristics. These factors have driven an interest in the in vitro propagation of this species, looking for germplasm bank maintenance, production of disease free plants, genetic variability induction from callus, and as a tool for starch research. However, there are few reports concerning the micropropagation of Curcuma longa. The in vitro propagation rate of this species, cultured under two benzylaminopurine (BAP) concentrations, was the aim of this research.

Resídue de polpas de frutas desidratadas na alimentação de leitões em fase de creche

It was evaluated chemically and biologically the powdered fruits pulp residue, used in human food industry. In the digestibility study it was used 12 commercial hybrids barrows piglets, with initial weight 12.2 ± 1,6 kg, allotted in individual cages. The treatments were a basal and a test diet. In the test diet the fruits pulp residue replaced 30% of the basal dry matter. The following values were obtained: dry matter 89,54%, starch 71,1%, glucose 5.4%, fructose 2,2%, crude protein 5,33%, gross energy 3771 kcal/kg, apparent digestible dry matter 96,01%, digestible energy 3448 kcal/kg, metabolizable energy 3389 kcal/kg. By bromatologic results and metabolism study, the powdered fruits pulp residue was characterized as an alternative to be evaluated in piglet diets. In the performance assay 90 piglets with initial weight of 6,60 ± 0,76 kg were allotted in a randomized block design, with six replications and three animals per experimental unit. The treatments were levels of powdered fruits pulp residue (0. 25, 50, 75 and 100%) replacing the corn of the control diet. The studied phases were initial-1 (14 days), initial-2 (21 days) and total period. On the performance there was no difference between the studied inclusion levels. For meal diets, the fruits pulp residue can replace the corn.

Production of CGTase by a bacillus Alkalophilic CGII strain isolated from wastewater of a manioc flour industry

GCTase production by a new strain of Bacillus alkalophillc CGII isolated from Brazilian wastewater of manioc flour industry was examined. The growth medium used was composed by 1.5% starch, 1.5% nitrogen and 1% Na 2CO3. Higher activity was obtained with starch, maltodextrin and galactose. When glucose was added to the medium, no enzyme production was observed. High enzyme activity and growth were reached when aeration was increased (88.6 U/mL). The enzyme characterization showed an optimum pH and temperature 8.0 and 55°C for starch hydrolyses, respectively. Mg+ and Ca++ showed small activation; however, Hg + and Cu+ showed a strong enzyme inhibition.

Carbon isotope composition and leaf anatomy as a tool to characterize the photosynthetic mechanism of Artemisia annua L.

Leaves of Artemisia annua L. are a plentiful source of artemisinin, a drug with proven effectiveness against malaria. The aim of this study was to classify the photosynthetic mechanism of A. annua through studies of the carbon isotope composition (δ 13C) and the leaf anatomy. A. annua presented a δ 13C value of - 31.76 ± 0.07, which characterizes the plants as a typical species of the C3 photosynthethic mechanism, considering that the average δ 13C values for C3 and C4 species are -28 and -14, respectively. The leaf anatomy studies were consistent with the δ 13C results, where, in spite of the existence of parenchymatic cells forming a sheath surrounding the vascular tissue, the cells do not contain chloroplasts or starch. This characteristic is clearly different from that of the Kranz anatomy found in C4 species.

Apparent digestibility of different ingredients in diets for bullfrog Rana catesbeiana tadpoles

The objective of this study was to determine apparent digestibility of protein and energy of ingredients commonly present in rations fed to bullfrog tadpoles Rana catesbeiana such as corn, soybean meal, wheat meal, rice bran, poultry by-product meal, blood meal, fish meal, corn starch and soybean oil. A completely randomized design was used to test ten experimental diets with four replicates. About 30% of the reference diet was replaced by the test ingredients, except for soybean oil that was used at 10% ratio and 0.5% of chromium oxide as inert marker. The values of apparent digestibility coefficient of crude protein (ADCCP) and gross energy (ADCGE) of the protein ingredients were, respectively: fish meal, 81 and 95%; poultry byproduct meal, 82 and 87%; blood meal, 64 and 53%; and soybean meal, 93 and 90%. While for the energetic ingredients, ADCCP and ADCGE, were, respectively: wheat meal, 100 and 72%; rice bran, 57 and 24%; and corn, 84 and 92%. Soybean oil and cornstarch ADCGE values were 70 and 96%, respectively; cornstarch digestibility is highly dependent on feed processing technique. The results showed that the ing redients of plant origin, except for rice bran, had good digestibility, thus indicating that tadpoles can effectively use plant protein. In this trial, the least digestible ingredients were blood meal and rice bran, thus indicating that the use of such ingredients in bullfrog tadpole diets should be limited. © Copyright by the World Aquaculture Society 2005.

Anelastic spectroscopy in TiO2

Titanium dioxide (rutile) has a lot of interesting and useful features and hence is widely utilized for application. It has been used as white pigment, photocatalyst, biocompatible material and semiconductor material used in solar battery. In semiconducting TiO2 oxygen vacancies are said to play an important role in the electrical conduction. Measurements of the elastic energy loss and modulus (anelastic spectroscopy) as a function of temperature can distinguish among the different atomic jumps, which occur in the various phases or at different local ordering. In this paper, it is reported anelastic relaxation measurements in TiO2 samples using a torsion pendulum operating in frequencies around 40Hz, in the temperature range between -173°C to 330°C with heating rate of 1°C/min. The results shown a reduction in the elasticity modulus with the increase in the corn starch content used for this consolidation.

Anelastic spectroscopy in Al2O3

Engineering ceramics have found use in many applications, such as engine parts, ball bearings, artificial bone and hip replacements and gyroscopes, because of their good chemical inertness, hardness, high temperature stability and excellent wear resistance. Oxide ceramic may meet these demands. Alumina (Al2O3) ceramics offer a high potential for many engineering applications, such as wear- and/or corrosion-resistant components, and as material for substrates or housings in microelectronic devices. Alumina is used among other things for seal ring, draw-cones, guides, water mixing tapes, bearing parts, medical prostheses and cutting tools. Measurements of the elastic energy loss and modulus (anelastic spectroscopy) as a function of temperature can distinguish among the different atomic jumps, which occurs in the various phases or at different local ordering. In this paper, it is reported anelastic relaxation measurements in Al2O3 samples using commercial starch. These measurements were carried out in a torsion pendulum operating in frequencies around 40 Hz. The results shown strongly influence of the type of forming in the elastic modulus obtained by anelastic relaxation measurements.

Production of saccharogenic and dextrinogenic amylases by Rhizomucor pusillus A 13.36

A newly-isolated thermophilic strain of the zygomycete fungus Rhizomucor pusillus 13.36 produced highly active dextrinogenic and saccharogenic enzymes. Cassava pulp was a good alternative substrate for amylase production. Dextrinogenic and saccharogenic amylases exhibited optimum activities at a pH of 4.0-4.5 and 5.0 respectively and at a temperature of 75°C. The enzymes were highly thermostable, with no detectable loss of saccharogenic or dextrinogenic activity after 1 h and 6 h at 60°C, respectively. The saccharogenic activity was inhibited by Ca2+ while the dextrinogenic was indifferent to this ion. Both activities were inhibited by Fe2+ and Cu2+ Hydrolysis of soluble starch by the crude enzyme yielded 66% glucose, 19.5% maltose, 7.7% maltotriose and 6.6% oligosaccharides. Copyright © 2005, The Microbiological Society of Korea.

Efeitos de parâmetros de extrusão nas propriedades físicas de produtos expandidos de inhame

Effect of extrusion parameters was studied on the expansion index, specific volume, water absorption index (WAI) and water solubility index (WSI) of expanded yam snacks. The central composite design was used to study the parameters effect. It was verified three levels of temperature in the barrel (100, 115 and 130°C), three levels of screw speed (163, 204 and 245 rpm) and three levels of flour moisture (12, 15 and 18%). The results showed that expansion properties (expansion index and specific volume) depend on flour moisture and extrusion temperature. The WSI was dependant of three parameters. Higher levels of temperature and screw speed increase the water solubility index (WSI). The studied parameters did not influence the water absorption index (WAI).