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排序方式: 共有316条查询结果,搜索用时 15 毫秒
301.
Lucas Diniz Giraldeli Bruna Constante Fonseca Valeria Reginatto 《International Journal of Hydrogen Energy》2018,43(49):22159-22169
Fermentative hydrogen production allows the use of renewable biomasses as feedstocks. However, biomass saccharification results not only in carbohydrates, but also in products that can inhibit fermentation. Although biomass hydrolysates contain mixtures of inhibitors, most studies are performed with a single inhibitor. This study evaluates how 5-hydroxymethylfurfural (HMF, 0.60 g/L), levulinic acid (LA, 2.10 g/L), and/or formic acid (FA, 0.80 g/L) mixtures affect two H2-producing clostridia, Clostridium beijerinckii Br21 and Clostridium acetobutylicum ATCC 824. Fermentation assays with and without (control) the inhibitors helped to calculate the specific H2 production, substrate consumption, and bacterial cell growth rates for Clostridium beijerinckii Br21 or Clostridium acetobutylicum ATCC 824. HMF + AL, HMF + AF, AL + AF, and HMF + AL + AF mixtures inhibited H2 production by C. beijerinckii Br21 by 58.7, 60.0, 46.9, and 83.0%, respectively, and by C. acetobutylicum ATCC 824 by 68.1, 71.4, 58.2, and 89.0%, respectively. Clostridium acetobutylicum ATCC 824 metabolized HMF more efficiently. However, organic acids and their combination with HMF inhibited H2 production by C. beijerinckii Br21 to a lesser extent, which highlighted that this microorganism is robust for H2 production from biomass hydrolysates. 相似文献
302.
Yang Zhou Philip Nash Samuel M. Bessa Guilherme Teodoro Ferrigatto Bruna Santos V. P. Madureira Aparecida Silva Magalhães Aline Oliveira Guilherme Carvalho Pereira Lorena Goncalves Ribeiro Lucas Pires dos Santos André Alves da Silva Jessica Dornelas Silva Andre Gonzalez Silva Jean Muniz de Souza Yuri Santorio Torres Raul Lima da Silva Barbara Fernanda Rievrs Fernandes de Cunha 《Journal of Phase Equilibria and Diffusion》2017,38(5):630-645
The phase equilibria in the Ni-Co rich region (<50 at.%Al) of the Al-Co-Ni system were studied experimentally for two isothermal sections at 1100 and 800 °C. Metallography, energy dispersive spectroscopy, hardness and x-ray diffraction were used for characterization and determination of γ, γ′ and β phases within the ternary system. Phase boundaries in the isothermal sections and a partial liquidus projection are modified compared to previously published work. Comparison is made to the isothermal sections computed using Thermo-Calc and the TCNI8 database. No definitive experimental evidence corroborating the predicted existence of a Nishizawa horn was obtained. 相似文献
303.
Ana Paula Daniel Ana Paula L. Veeck Bruna Klein Lauren F. Ferreira Mauro A. da Cunha Thaylise V. Parodi Carla C. Zeppenfeld Denise Schmidt Braulio O. Caron Berta M. Heinzmann Bernardo Baldisserotto Tatiana Emanuelli 《Journal of food science》2014,79(6):S1205-S1211
Exposure of silver catfish to 40 μL/L of the essential oil of Aloysia triphylla (AT) during in vivo transport delayed the onset and resolution of rigor mortis as well as the degradation of IMP into HxR compared to the control. The fish that were treated with 30 or 40 μL/L of AT received lower sensory demerit scores after 10 d of storage in ice compared to the control, and the fish that were treated with 40 μL/L of AT had a longer sensory shelf life than did the control. These results indicated that using AT as a sedative in the water in which the silver catfish were transported extended their freshness and increased their shelf life during refrigerated storage. 相似文献
304.
The aim of the present work was to enhance the degradation of free amino acids in dry fermented sausages as precursors of volatile compounds responsible for the ripened flavour. For this purpose, Lactococcus lactis subsp. cremoris NCDO 763, its intracellular cell free extract (ICFE) and α-ketoglutarate were added to sausages. Papain was also used to increase the amount of free amino acids. When L. lactis was inoculated in sausages, an increase in the proteolytic phenomena was observed. The addition of α-ketoglutarate increased transamination phenomena in batches where it was added. The enhancement of these phenomena determined a noticeable rise in the content of glutamic acid (the main final product in transamination reactions) and a decrease, among other amino acids, of valine and leucine, with the formation of high amounts of their derivatives 2-methylpropanal and 3-methylbutanal. These aldehydes are responsible for the ripened flavour of dry fermented sausages. Sensory analysis showed an improvement of odour and flavour when L. lactis and α-ketoglutarate were combined. On the other hand, the intracellular cell free extract of L. lactis did not show any important activity in relation to amino acid breakdown even when used together with α-ketoglutarate and/or papain. 相似文献
305.
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307.
Bruna Vieira Cabral Líbia Diniz Santos Larissa N. S. Santana Falleiros Taciana S. Carmo Fernanda Ferreira Freitas Saulo Luiz Cardoso 《Chemical Engineering Communications》2017,204(9):1007-1019
The conversion of sucrose to a highly concentrated commercial syrup by immobilized invertase by combining the processes of adsorption and cross-linking using Duolite A-568 as the carrier was studied. Central Composite Design (CCD) was used to assess the effect of glutaraldehyde concentration and cross-linking reaction time on immobilized enzyme activity throughout the hydrolysis of sucrose in a batch reactor. Cross-linking optimization allowed us to find the optimum conditions for activity with a glutaraldehyde concentration of 0.6?g?·?L?1 and a cross-linking time of 6?h. The temperature and pH that maximized the activity of the immobilized biocatalyst in the cross-linking process were 50°C and 4.0, respectively. Cross-linking allows the biocatalyst to be active at higher temperatures and lower pH. High-sucrose conversions to invert sugar using a continuous fixed-bed reactor were obtained. The immobilized biocatalyst also demonstrated greater thermal stability at low temperatures. 相似文献
308.
Christiano de C. Lamb Bruna Martini Zacarias da Silva Diego de Souza Franccesca Fornasier Larissa Brixner Riça 《Chemical Engineering Communications》2018,205(6):833-845
The objective of this research was to produce bioethanol from rice hulls and to evaluate the recovery and potential use of the residue resulting from the enzymatic hydrolysis step before fermentation. Acid pretreatment and enzymatic hydrolysis were studied for saccharification of polysaccharides. Fermentation was conducted for up to 24?h with Saccharomyces cerevisiae yeast. After process optimization, it was possible to produce >7.0?mg?mL?1 of ethanol after only 2?h of reaction. Characterization of the solid residues from the hydrolyzed rice husk and the in natura rice husk showed that these solids have different characteristics and present different adsorption potentials because the residue has higher silica content. The product has potential use in industrial or laboratorial adsorption processes. The results from this study offer support for the potential use of rice husks for bioethanol generation and use the solid residue from hydrolysis for adsorption. 相似文献
309.
310.
Fernando Guedes Mariana V. Branquinho Sara Biscaia Rui D. Alvites Ana C. Sousa Bruna Lopes Patrícia Sousa Alexandra Rêma Irina Amorim Ftima Faria Tatiana M. Patrício Nuno Alves Antnio Bugalho Ana C. Maurício 《International journal of molecular sciences》2022,23(24)
Additive manufacturing or 3D printing applying polycaprolactone (PCL)-based medical devices represents an important branch of tissue engineering, where the sterilization method is a key process for further safe application in vitro and in vivo. In this study, the authors intend to access the most suitable gamma radiation conditions to sterilize PCL-based scaffolds in a preliminary biocompatibility assessment, envisioning future studies for airway obstruction conditions. Three radiation levels were considered, 25 kGy, 35 kGy and 45 kGy, and evaluated as regards their cyto- and biocompatibility. All three groups presented biocompatible properties, indicating an adequate sterility condition. As for the cytocompatibility analysis, devices sterilized with 35 kGy and 45 kGy showed better results, with the 45 kGy showing overall improved outcomes. This study allowed the selection of the most suitable sterilization condition for PCL-based scaffolds, aiming at immediate future assays, by applying 3D-customized printing techniques to specific airway obstruction lesions of the trachea. 相似文献