New fuel cells system for portable application with low temperature cofired ceramic (LTCC) technology

Miniature direct methanol fuel cells (DMFCs) are promising micro power sources for portable appliction. Low temperature cofired ceramic (LTCC), a competitive technology for current MEMS based fabrication, provides cost-effective mass manufacturing route for miniature DMFCs. Porous silver tape is adapted as electrodes to replace the traditional porous carbon electrodes due to its compatibility to LTCC processing and other electrochemical advantages. Electrochemical evaluation of silver under DMFCs operating conditions demonstrated that silver is a good electrode for DMFCs because of its reasonable corrosion resistance, low passivating current, and enhanced catalytic effect. Two catalyst loading methods (cofiring and postfiring) of the platinum and ruthenium catalysts are evaluated for LTCC based processing. The electrochemical analysis exhibits that the cofired path out-performs the postfiring path both at the anode and cathode. The reason is the formation of high surface area precipitated whiskers. Self-constraint sintering is utilized to overcome the difficulties of the large difference of coefficient of thermal expansion (CTE) between silver and LTCC (Dupont 951) tape during cofiring. The graphite sheet employed as a cavity fugitive insert guarantees cavity dimension conservation. Finally, performance of the membrane electrode assembly (MEA) with the porous silver electrode in the regular graphite electrode based cell and the integrated cofired cell is measured under passive fuel feeding condition. The MEA of the regular cell performs better as the electrode porosity and temperature increased. The power density of 10 mWcm-2 was obtained at ambient conditions with 1M methanol and it increased to 16 mWcm -2 at 50��C from an open circuit voltage of 0.58V. For the integrated prototype cell, the best performance, which depends on the balance methanol crossover and mass transfer at different temperatures and methanol concentrations, reaches 1.13 mWcm-2 at 2M methanol solution at ambient pressure. The porous media pore structure increases the methanol crossover resistance. As temperature increased to 60��C, the device increases to 2.14 mWcm-2.

Avalia����o do potencial da fibra e casca de coco maduro, casca de coco verde e cacto pr��-tratados visando �� produ����o de etanol

The present work investigated the potential of different residual lignocellulosic materials generated in rural and urban areas (coconut fibre mature, green coconut shell and mature coconut shell), and vegetable cultivated in inhospitable environments (cactus) aimed at the production of ethanol, being all materials abundant in the Northeast region of Brazil. These materials were submitted to pretreatments with alkaline hydrogen peroxide followed by sodium hydroxide (AHP-SHP), autohydrolysis (AP), hydrothermal catalyzed with sodium hydroxide (HCSHP) and alkali ethanol organosolv (AEOP). These materials pretreated were submitted to enzymatic hydrolysis and strategies of simultaneous saccharification and fermentation (SSF) and saccharification and fermentation semi-simultaneous (SSSF) by Saccharomyces cerevisiae, Zymomonas mobilis and Pichia stipitis. It was also evaluated the presence of inhibitory compounds (hydroxymethylfurfural, furfural, acetic acid, formic acid and levulinic acid) and seawater during the fermentative process. Materials pretreated with AHP-SHP have resulted in delignification of the materials in a range between 54 and 71%, containing between 51.80 and 54.91% of cellulose, between 17.65 and 28.36% of hemicellulose, between 7.99 and 10.12% of lignin. Enzymatic hydrolysis resulted in the conversions in glucose between 68 and 76%. Conversion yields in ethanol using SSF and SSSF for coconut fibre mature pretreated ranged from 0.40 and 0.43 g/g, 0.43 and 0.45 g/g, respectively. Materials pretreated by AP showed yields of solids between 42.92 and 92.74%, containing between 30.65 and 51.61% of cellulose, 21.34 and 41.28% of lignin. Enzymatic hydrolysis resulted in glucose conversions between 84.10 and 92.52%. Proceeds from conversion into ethanol using green coconut shell pretreated, in strategy SSF and SSSF, were between 0.43 and 0.45 g/g. Coconut fibre mature pretreated by HCSHP presented solids yields between 21.64 and 60.52%, with increased in cellulose between 28.40 and 131.20%, reduction of hemicellulose between 43.22 and 69.04% and reduction in lignin between 8.27 and 89.13%. Enzymatic hydrolysis resulted in the conversion in glucose of 90.72%. Ethanol yields using the SSF and SSSF were 0.43 and 0.46 g/g, respectively. Materials pretreated by AEOP showed solid reductions between 10.75 and 43.18%, cellulose increase up to 121.67%, hemicellulose reduction up to 77.09% and lignin reduced up to 78.22%. Enzymatic hydrolysis resulted in the conversion of glucose between 77.54 and 84.27%. Yields conversion into ethanol using the SSF and SSSF with cactus pretreated ranged from 0.41 and 0.44 g/g, 0.43 and 0.46 g/g, respectively. Fermentations carried out in bioreactors resulted in yields and ethanol production form 0.42 and 0.46 g/g and 7.62 and 12.42 g/L, respectively. The inhibitory compounds showed negative synergistic effects in fermentations performed by P. stipitis, Z. mobilis and S. cerevisiae. Formic acid and acetic acid showed most significant effects among the inhibitory compounds, followed by hydroxymethylfurfural, furfural and levulinic acid. Fermentations carried out in culture medium diluted with seawater showed promising results, especially for S. cerevisiae (0.50 g/g) and Z. mobilis (0.49 g/g). The different results obtained in this study indicate that lignocellulosic materials, pretreatments, fermentative processes strategies and the microorganisms studied deserve attention because they are promising and capable of being used in the context of biorefinery, aiming the ethanol production.

Trissoralen um medicamento de baixa dosagem: estudos termoanal��ticos da compatibilidade do f��rmaco-excipientes e determina����o de par��metros de qualidade para c��psulas magistrais

The trioxsalen (Tri) is a low-dose drug used in the treatment of psoriasis and other skin diseases. The aim of the study was applying the thermal analysis and complementary techniques for characterization, evaluation of the trioxsalen stability and components of manipulated pharmaceutical formulations. The thermal behavior of the Tri by TG/DTG-DTA in dynamic atmosphere of synthetic air and nitrogen showed the same profile with a melting peak followed by a volatilization-related event. From the curves TG / DTG is observed a single stage of mass loss. By heating the drug in the stove at temperatures of 80, 240 and 260 ��C, it had no change in chemical structure through the techniques of XRD, HPLC, MIR, OM and SEM. From the non-isothermal and isothermal TG kinetic studies was possible to calculate the activation energy and reaction order for the Tri. The drug showed good thermal stability. Studies on drug-excipient compatibility showed interaction of trissoralen with sodium lauryl sulfate 1:1. There was no interaction with aerosol, pregelatinized starch, sodium starch glycolate, cellulose, croscarmellose sodium, magnesium stearate, lactose and mannitol.The characterization of three trioxsalen formulations at concentrations of 2.5, 5, 7.5, 10, 12.5 and 15 mg was performed by DSC, TG / DTG, XRD, NIR and MIR. The PCA classification method based on spectral data from the NIR and MIR of trissoralen formulations allows successful differentiation into three groups. The formulation 3 was the one that best showed analytical profile with the following composition of aerosil excipients, pre-gelatinized starch and cellulose. The activation energy of the volatilization process of the drug was determined in binary mixtures and formulation 3 through fitting and isoconversional methods. The binary mixture with sodium starch glycolate and lactose showed differences in kinetic parameters compared to the drug isolated. The thermoanalytical techniques (DSC and TG / DTG) were shown to be promising methodologies for quantifying trioxsalen obtained by the linearity, selectivity, no use solvents, without sample preparation, speed and practicality.

Estudo experimental e modelagem do processo de sacarifica����o e fermenta����o simult��nea utilizando baga��o de cana-de-a����car para produ����o de etanol

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico - CNPq

Avalia����o da influ��ncia de surfactantes qu��mico e biol��gico na hidr��lise enzim��tica de casca de coco verde ap��s pr��-tratamento ��cido/alcalino e com per��xido de hidrog��nio alcalino

In Brazil many types of bioproducts and agroindustrial waste are generated currently, such as cacashew apple bagasse and coconut husk, for example. The final disposal of these wastes causes serious environmental issues. In this sense, waste lignocellulosic content, as the shell of the coconut is a renewable and abundant raw material in which its use has an increased interest mainly for the 2nd generation ethanol production. The hydrolysis of cellulose to reducing sugars such as glucose and xylose is catalysed by a group of enzymes called cellulases. However, the main bottleneck in the enzymatic hydrolysis of cellulose is the significant deactivation of the enzyme that shows irreversible adsorption mechanism leading to reduction of the cellulose adsorption onto cellulose. Studies have shown that the use of surfactants can modify the surface property of the cellulose therefore minimizing the irreversible binding. The main objective of the present study was to evaluate the influence of chemical and biological surfactants during the hydrolysis of coconut husk which was subjected to two pre-treatment in order to improve the accessibility of the enzymes to the cellulose, removing this way, part of the lignin and hemicellulose present in the structure of the material. The pre-treatments applied to coconut bagasse were: Acid/Alkaline using 0.6M H2SO4 followed by 1M NaOH, and the one with Alkaline Hydrogen Peroxide at a concentration of 7.35% (v/v) and pH 11.5. Both the material no treatment and pretreated were characterized using analysis of diffraction X-ray (XRD), Scanning Electron Microscopy (SEM) and methods established by NREL. The influence of both surfactants, chemical and biological, was used at concentrations below the critical micelle concentration (CMC), and the concentrations equal to the CMC. The application of pre-treatment with coconut residue was efficient for the conversion to glucose, as well as for the production of total reducing sugars, it was possible to observe that the pretreatment fragmented the structure as well as disordered the fibers. Regarding XRD analysis, a significant increase in crystallinity index was observed for pretreated bagasse acid/alkali (51.1%) compared to the no treatment (31.7%), while that for that treated with PHA, the crystallinity index was slightly lower, around 29%. In terms of total reducing sugars it was not possible to observe a significant difference between the hydrolysis carried out without the use of surfactant compared to the addition of Triton and rhamnolipid. However, by observing the conversions achieved during the hydrolysis, it was noted that the best conversion was using the rhamnolip��d for the husk pretreated with acid/alkali, reaching a value of 33%, whereas using Triton the higher conversion was 23.8%. The coconut husk is a residue which can present a high potential to the 2nd generation ethanol production, being the rhamonolipid a very efficient biosurfactant for use as an adjuvant in the enzymatic process in order to act on the material structure reducing its recalcitrance and therefore improving the conditions of access for enzymes to the substrate increasing thus the conversion of cellulose to glucose.

Avalia����o da influ��ncia de surfactantes qu��mico e biol��gico na hidr��lise enzim��tica de casca de coco verde ap��s pr��-tratamento ��cido/alcalino e com per��xido de hidrog��nio alcalino

In Brazil many types of bioproducts and agroindustrial waste are generated currently, such as cacashew apple bagasse and coconut husk, for example. The final disposal of these wastes causes serious environmental issues. In this sense, waste lignocellulosic content, as the shell of the coconut is a renewable and abundant raw material in which its use has an increased interest mainly for the 2nd generation ethanol production. The hydrolysis of cellulose to reducing sugars such as glucose and xylose is catalysed by a group of enzymes called cellulases. However, the main bottleneck in the enzymatic hydrolysis of cellulose is the significant deactivation of the enzyme that shows irreversible adsorption mechanism leading to reduction of the cellulose adsorption onto cellulose. Studies have shown that the use of surfactants can modify the surface property of the cellulose therefore minimizing the irreversible binding. The main objective of the present study was to evaluate the influence of chemical and biological surfactants during the hydrolysis of coconut husk which was subjected to two pre-treatment in order to improve the accessibility of the enzymes to the cellulose, removing this way, part of the lignin and hemicellulose present in the structure of the material. The pre-treatments applied to coconut bagasse were: Acid/Alkaline using 0.6M H2SO4 followed by 1M NaOH, and the one with Alkaline Hydrogen Peroxide at a concentration of 7.35% (v/v) and pH 11.5. Both the material no treatment and pretreated were characterized using analysis of diffraction X-ray (XRD), Scanning Electron Microscopy (SEM) and methods established by NREL. The influence of both surfactants, chemical and biological, was used at concentrations below the critical micelle concentration (CMC), and the concentrations equal to the CMC. The application of pre-treatment with coconut residue was efficient for the conversion to glucose, as well as for the production of total reducing sugars, it was possible to observe that the pretreatment fragmented the structure as well as disordered the fibers. Regarding XRD analysis, a significant increase in crystallinity index was observed for pretreated bagasse acid/alkali (51.1%) compared to the no treatment (31.7%), while that for that treated with PHA, the crystallinity index was slightly lower, around 29%. In terms of total reducing sugars it was not possible to observe a significant difference between the hydrolysis carried out without the use of surfactant compared to the addition of Triton and rhamnolipid. However, by observing the conversions achieved during the hydrolysis, it was noted that the best conversion was using the rhamnolip��d for the husk pretreated with acid/alkali, reaching a value of 33%, whereas using Triton the higher conversion was 23.8%. The coconut husk is a residue which can present a high potential to the 2nd generation ethanol production, being the rhamonolipid a very efficient biosurfactant for use as an adjuvant in the enzymatic process in order to act on the material structure reducing its recalcitrance and therefore improving the conditions of access for enzymes to the substrate increasing thus the conversion of cellulose to glucose.

Giant piezoresistance in silicon-germanium alloys

We use first-principles electronic structure methods to show that the piezoresistive strain gauge factor of single-crystalline bulk n-type silicon-germanium alloys at carefully controlled composition can reach values of G = 500, three times larger than that of silicon, the most sensitive such material used in industry today. At cryogenic temperatures of 4 K we find gauge factors of G = 135 000, 13 times larger than that observed in Si whiskers. The improved piezoresistance is achieved by tuning the scattering of carriers between different (Delta and L) conduction band valleys by controlling the alloy composition and strain configuration.

A nicotina atua como fator delet��rio na repara����o da parede abdominal

Objetivo: Avaliar o efeito da nicotina na cicatriza����o da camada musculoaponeur��tica da parede abdominal. M��todos: Estudo experimental em que foram usados 16 ratos da ra��a Wistar pesando em m��dia 210��8g, separados aleatoriamente em 2 grupos de 8. Nos animais do grupo A foi implantado disco de nicotina (Nicotinel ��) na dose de 5mg/Kg de peso/dia no subcut��neo da regi��o dorsal, trocado a cada dois dias, a partir do 5�� dia antes da opera����o em que foi feita laparotomia mediana de 5 cm, at�� o 10o dia de observa����o. No grupo B (controle) foram usados discos de celulose com o mesmo di��metro. Tubo de silicone multiperfurado foi implantado no subcut��neo a 1cm da les��o da parede abdominal. A camada musculoaponeur��tica e a pele foram suturadas com fio de nylon 5-0. No 10�� dia p��s-operat��rio foi colhido 1ml de l��quido seroso do tubo de silicone por pun����o percut��nea para dosagem de pO2 e os animais receberam dose letal de anest��sico. Foi ressecado um segmento da camada musculoaponeur��tica com 2cm de largura para tensiometria, em seguida processado e corado em HE e tricr��mico de Masson para an��lise quantitativa dos dados histopatol��gicos em sistema digitalizado. A an��lise estat��stica foi feita pelo ANOVA e teste Newman-Keuls, com signific��ncia 0,05. Resultados: No grupo A a pO2 do l��quido tecidual atingiu o valor 17,75��3,4 mmHg e no grupo B (controle) a pO2 = 40,75��6,4 mmHg (p<0,01). A resist��ncia �� tens��o apresentou o valor de 728,5��161,75gf no grupo A e 1241,6��232gf no grupo de controle (p<0,01), coincidindo com os achados da pO2. A densidade m��dia dos elementos histopatol��gicos estudados foi de 105��17,1 nos animais do grupo A e 146,2��8,8 no grupo B (p<0,01). Conclus��o: ap��s avalia����o da pO2 tecidual, tensiometria e histopatologia, concluiu-se que a nicotina por via subcut��nea exerce efeito delet��rio sobre a cicatriza����o de les��es da parede abdominal de ratos

Isolation and selection of plant growth-promoting bacteria associated with sugarcane

v. 46, n. 2, p. 149-158, apr./jun. 2016.

Alternativas de uso da borra de caf�� atrav��s de hidr��lise ��cida, enzim��tica, ou como substrato para a produ����o das enzimas: lacase e celulase

In the industrial production of soluble coffee, huge amounts of extracted coffee residues are generated; onaverage, for eachtonne of green coffee extracted, 480 kg of coffee ground waste is produced. This is a solid residue currently used to generate energy at the steam boilers from the soluble coffee industry. Some is also used or as fertilizer on agriculture fields. Seeking a better end use, the work reported here aimed to study the viability of hydrolyzing the coffee ground residue for the production of carbohydrates. Hydrolysis was undertaken with hydrochloric acid at different temperatures and pressures, using a water bath or autoclave.An enzymatic hydrolysis with Viscozyme Lwas developed using Whatman filter paper No1 and the optimal conditions were determined using a rotational central composite experimental design (DCCR).The best conditions to hydrolyze filter paper cellulose were 50 FBG (Fungal ��-glucanase) of Viscozyme L at pH 4.0 for 1.0 h and 45 ��C. The ground coffee was hydrolyzed under the same conditions as described above for filter paper, however this enzymatic hydrolysis was not efficient. A combination of enzymatic hydrolysis as a pre-treatment for the ground coffee followed by acid hydrolysis using HCl conducted in an autoclave (120 ���C for 2.0 h) resulted in higher production of glucose as analyzed by HPLC. Another end use of the ground coffee evaluated was as source of substrate in the culture medium to grow Botryosphaeria rhodina MAMB-05 to produce the enzymes laccase and cellulase. Highest enzyme titres obtained were with 8% (w/v) coffee grounds to which was added a minimum salts medium(Vogel), under agitation conditions (180 rpm) at 28��C. The phenolic compounds present in the coffee grounds appear to have induced laccase by Botryosphaeria rhodina.

A nicotina atua como fator delet��rio na repara����o da parede abdominal

Objetivo: Avaliar o efeito da nicotina na cicatriza����o da camada musculoaponeur��tica da parede abdominal. M��todos: Estudo experimental em que foram usados 16 ratos da ra��a Wistar pesando em m��dia 210��8g, separados aleatoriamente em 2 grupos de 8. Nos animais do grupo A foi implantado disco de nicotina (Nicotinel ��) na dose de 5mg/Kg de peso/dia no subcut��neo da regi��o dorsal, trocado a cada dois dias, a partir do 5�� dia antes da opera����o em que foi feita laparotomia mediana de 5 cm, at�� o 10o dia de observa����o. No grupo B (controle) foram usados discos de celulose com o mesmo di��metro. Tubo de silicone multiperfurado foi implantado no subcut��neo a 1cm da les��o da parede abdominal. A camada musculoaponeur��tica e a pele foram suturadas com fio de nylon 5-0. No 10�� dia p��s-operat��rio foi colhido 1ml de l��quido seroso do tubo de silicone por pun����o percut��nea para dosagem de pO2 e os animais receberam dose letal de anest��sico. Foi ressecado um segmento da camada musculoaponeur��tica com 2cm de largura para tensiometria, em seguida processado e corado em HE e tricr��mico de Masson para an��lise quantitativa dos dados histopatol��gicos em sistema digitalizado. A an��lise estat��stica foi feita pelo ANOVA e teste Newman-Keuls, com signific��ncia 0,05. Resultados: No grupo A a pO2 do l��quido tecidual atingiu o valor 17,75��3,4 mmHg e no grupo B (controle) a pO2 = 40,75��6,4 mmHg (p<0,01). A resist��ncia �� tens��o apresentou o valor de 728,5��161,75gf no grupo A e 1241,6��232gf no grupo de controle (p<0,01), coincidindo com os achados da pO2. A densidade m��dia dos elementos histopatol��gicos estudados foi de 105��17,1 nos animais do grupo A e 146,2��8,8 no grupo B (p<0,01). Conclus��o: ap��s avalia����o da pO2 tecidual, tensiometria e histopatologia, concluiu-se que a nicotina por via subcut��nea exerce efeito delet��rio sobre a cicatriza����o de les��es da parede abdominal de ratos

Modifica����o da pasta kraft de eucalipto para novas aplica����es

Este trabalho constou num estudo da modifica����o da pasta kraft de eucalipto, utilizando uma t��cnica de processamento por alta press��o hidrost��tica com o intuito de melhorar a sua performance para novas aplica����es tal como o papel tissue ou o papel para embalagens. Para tal pretendia-se melhorar algumas propriedades da pasta com a utiliza����o da t��cnica de alta press��o hidrost��tica. Realizou-se um estudo preliminar onde se submeteu uma pasta branqueada A, n��o refinada, a um tratamento hiperb��rico (TH) numa gama de press��es de 5000-8000 bar. Para uma press��o de 6000 bar constatou-se uma melhoria de cerca de 16 % no alongamento percentual na rotura, 17 % na resist��ncia �� tra����o, 27 % no ��ndice de rebentamento e cerca de 19 % no ��ndice de rasgamento. Posteriormente, e tendo em conta os resultados positivos verificados na pasta A, estudou-se o efeito do TH numa pasta branqueada B variando a consist��ncia de tratamento (1,5% ou 3%) e o tempo de processamento (5 ou 10 minutos). Foi estudado tamb��m o efeito do TH quando aplicado antes e ap��s a refina����o da pasta. A pasta branca foi submetida �� refina����o num moinho PFI entre 1000 e 3000 rota����es. Os resultados obtidos mostram que o TH realizado a menores consist��ncias apresenta um efeito mais significativo nas propriedades f��sico-mec��nicas de pastas e que o efeito �� distinto quando o processamento �� aplicado antes e depois da refina����o, tendo-se registado melhoramentos das propriedades mec��nicas apenas quando o TH ocorre ap��s a refina����o. A pasta kraft foi tamb��m modificada com anidrido alquenil succ��nico (ASA). A modifica����o da pasta de celulose com ASA resultou numa diminui����o das propriedades mec��nicas e para al��m disso n��o gerou qualquer altera����o na termoplasticidade do material, no entanto registou-se um aumento na resist��ncia �� molhabilidade. Concluiu-se que o TH conduz a altera����es ao n��vel de propriedades mec��nicas e estruturais da pasta de interesse para a aplica����o em pap��is tissue no caso da pasta B. Para al��m disso a modifica����o da pasta com ASA resultou em altera����es de interesse particular para pap��is de embalagem.

Enzymatic upgrading of eucalypt paper-grade kraft pulp within dissolving pulp production

Dissolving-grade pulps are commonly used for the production of cellulose derivatives and regenerated cellulose. High cellulose content, low content of non-cellulosic material, high brightness, a uniform molecular weight distribution and high cellulose reactivity are the key features that determine the quality of a dissolving pulp. The first part of this work was an optimization study regarding the application of selected enzymes in different stages of a new purification process recently developed in Novozymes for purifying an eucalypt Kraft pulp into dissolving pulp, as an alternative to the pre-hydrolysis kraft (PHK) process. In addition, a viscosity reduction was achieved by cellulase (endoglucanase) treatment in the beginning of the sequence, while the GH11 and GH10 xylanases contributed to boost the brightness of the final pulp. The second part of the work aimed at exploring different auxiliary enzyme activities together with a key xylanase towards further removal of recalcitrant hemicelluloses from a partially bleached Eucalypt Kraft pulp. The resistant fraction (ca. 6% xylan in pulp) was not hydrolysable by the different combinations of enzymes tested. Production of a dissolving pulp was successful when using a cold caustic extraction (CCE) stage in the end of the sequence O-X-DHCE-X-HCE-D-CCE. The application of enzymes improved process efficiency. The main requirements for the production of a dissolving pulp (suitable for viscose making) were fulfilled: 2,7% residual xylan, 92,4% of brightness, a viscosity within the values of a commercial dissolving pulp and increased reactivity.

Purifica����o e caracteriza����o parcial de uma B-D glicosidase de Artemia franciscana com a����o sobre celobiose e lactose

���-D-glucosidase (EC 3.2.1.21) is one of the most interesting glycosidases, especially for hydrolysis cellobiose releasing glucose, is last step degradation of cellulose. This function makes the ���-D-glucosidase is of great interest as a versatile industrial biocatalyst, being critical to various bio-treatment / biorefinery processes, such as bioethanol production. Hen in the report, a ���-D-glucosidase was extracts from protein extracted of the invertebrate marine Artemia franciscana was purified and characterized with a combination of precipitation with ammonium sulfate (0 - 30%, 30 to 50%, 50 to 80%), the fraction saturated in the range of 30 to 50% (called F-II) was applied in a molecular exclusion chromatography, in Sephacryl S-200, the fractions corresponding to the first peak of activity of ���-D-glucosidase were gathered and applied in a chromatography of ion exchange in Mono Q; the third peak this protein obtained chromatography, which coincides with the peak of activity of ���-D-glucosidase was held and applied in a gel filtration chromatography Superose 12 where the first peak protein, which has activity of ���-D-glucosidase was rechromatography on Superose 12. This enzyme is probably multimerica, consisting of three subunit molecular mass of 52.7 kDa (determined by SDS-PAGE) with native molecular mass of 157 kDa (determined by gel filtration chromatography on Superose 12 under the system FPLC). The enzyme was purified 44.09 times with a recovery of 1.01%. Using up p-nitrophenyl-��-D-glucopiranoside as substrate obtained a Km apparent of 0.229 mM and a Vmax of 1.109 mM.60min-1.mL-1mM. The optimum pH and optimum temperature of catalysis of the synthetic substrate were 5.0 and 45 ��C, respectively. The activity of the ���-D-glucosidase was strongly, inhibited by silver nitrate and N- etylmaleimide, this inhibition indicates the involvement of radical sulfidrila the hydrolysis of synthetic substrate. The ���-D-glucosidase of Artemia franciscana presented degradativa action on celobiose, lactose and on the synthetic substrate ���-nitrophenyl-��-D-glucopiranoside indicating potential use of this enzyme in the industry mainly for the production of bioethanol (production of alcohol from the participating cellulose), and production hydrolysate milk (devoid of milk lactose)

MULTIPLICA����O E ALONGAMENTO IN VITRO DE CLONES H��BRIDOS DE Eucalyptus globulus

Os h��bridos de Eucalyptus globulus representam uma excelente alternativa para o setor de celulose e papel, em raz��o dos ganhos em qualidade da madeira para a fabrica����o de celulose. Entretanto, estes h��bridos t��m apresentado recalcitr��ncia ao enraizamento advent��cio. Assim, a micropropaga����o �� apontada como a t��cnica para o rejuvenescimento desses h��bridos adultos, viabilizando a propaga����o clonal dos mesmos. O presente trabalho avaliou o cultivo in vitro de tr��s clones de Eucalyptus grandis x Eucalyptus globulus e de tr��s clones de Eucalyptus urophylla x Eucalyptus globulus, em rela����o �� multiplica����o in vitro, no meio MS suplementado com 0,5 mg L-1 de BAP e 0,01 mg L-1 de ANA, bem como o efeito das concentra����es de 0,25; 0,50; 0,75 e 1,0 mg L-1 de AIB e dos meios de cultura MS e JADS no alongamento in vitro das brota����es. Os clones diferiram quanto �� multiplica����o in vitro das brota����es e apresentaram uma taxa de multiplica����o m��dia dos clones de 3,0 tufos de brota����es em cada subcultivo, ao longo dos 25 subcultivos realizados. No alongamento in vitro, os clones diferiram quanto ��s concentra����es de AIB adequadas para provocar o alongamento, bem como em rela����o aos meios de cultura MS e JADS. O intervalo m��dio entre 0,40 e 0,80 mg L-1 de AIB proporcionou o maior n��mero e comprimento das brota����es alongadas in vitro e com maior vigor.