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| Registros recuperados: 43 | |
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| Thimoteo,S.S.; Glogauer,A.; Faoro,H.; de Souza,E.M.; Huergo,L.F.; Moerschbacher,B.M.; Pedrosa,F.O.. |
| Chitinases are hydrolases that degrade chitin, a polymer of N-acetylglucosamine linked β(1-4) present in the exoskeleton of crustaceans, insects, nematodes and fungal cell walls. A metagenome fosmid library from a wastewater-contaminated soil was functionally screened for chitinase activity leading to the isolation and identification of a chitinase gene named metachi18A. The metachi18A gene was subcloned and overexpressed in Escherichia coli BL21 and the MetaChi18A chitinase was purified by affinity chromatography as a 6xHis-tagged fusion protein. The MetaChi18A enzyme is a 92-kDa protein with a conserved active site domain of glycosyl hydrolases family 18. It hydrolyses colloidal chitin with an optimum pH of 5 and temperature of 50°C. Moreover, the enzyme... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chitinase; Metagenomic; Aeromonas; Kinetics. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2017000100602 |
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| Lalitendu Das; North Carolina State University Biological and Agricultural Engineering; Praveen Kolar; North Carolina State University; Jason Osborne; North Carolina State University Department of Statistics; John Classen; North Carolina State University Biological and Agricultural Engineering. |
| Swine farming emit several odorous volatile organic compounds, one of which is p-cresol. Considering the layout of a swine barn, adsorption is one of the most suitable technologies for mitigating organic pollutants. In this study, commercial granular activated carbon (GAC) was tested as an adsorbent for removing p-cresol from aqueous solution. The objectives were to: 1) determine the combined effect of temperature, pH, and adsorbent dose on adsorption, (2) investigate the effect of volatile fatty acids and aldehydes on adsorption of p-cresol, (3) determine adsorption kinetics and isotherms, (4) study the effect of solvent on adsorption, (5) propose a possible mechanism of adsorption, and (6) discuss practical implications and design calculations for... |
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Palavras-chave: Agricultural Engineering Adsorption; P-cresol; Activated carbon; Kinetics; Isotherms; RSM. |
| Ano: 2012 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/2171 |
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| Borderes,Josiane; Costa,Alessandra; Guedes,Alessandro; Tavares,Lorena Benathar Ballod. |
| The aim of this work was to study the production of compounds with antioxidant activity by Pycnoporus sanguineus when cultivated in submerged fermentation using a potato dextrose broth plus peptone medium. The study evaluated the biomass production, glucose consumption, variation of medium pH and antioxidant activity. The antioxidant potential was tested through the DPPH method and β-carotene / linoleic acid system with extracts obtained from the mycelium at different times of cultivation (5, 10, 15, 20, 25 and 30 days). Maximum kinetic values of specific growth rate (0.289 day-1), biomass productivity (0.698 g.L-1.day-1) and the yield of glucose conversion into biomass (26.24 g.g-1) were obtained during the exponential growth phase. The highest... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Basidiomycetes; Submerged culture; Kinetics; Antioxidant compounds. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000600012 |
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| Qaiser,Suleman; Saleemi,Anwar R; Umar,Muhammad. |
| The biosorption of lead(II) and chromium(VI) on groundnut hull was investigated. Batch biosorption experiments were conducted to find the equilibrium time and biosorption capacity. Effect of parameters like pH, temperature and initial metal concentration was studied. The maximum biosorption capacity of lead(II) and chromium(VI) was found to be 31.54 ± 0.63 and 30.21 ± 0.74 mg g-1, respectively. The optimum pH for lead(II) and chromium(VI) removal was 5 ± 0.1 and 2 ± 0.1, respectively. The temperature change, in the range of 20 - 45ºC affected the biosorption capacity. The maximum removal of lead(II) was achieved at 20 ± 2ºC, where as maximum uptake of chromium(VI) was observed at 40 ± 2ºC. The biosorption data was fitted to the Langmuir and the Freundlich... |
| Tipo: Journal article |
Palavras-chave: Biosorption; Equilibrium; Groundnut hull; Kinetics; Thermodynamics. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582009000400003 |
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| Oliva-Merencio,Deny; Pereda-Reyes,Ileana; Schimpf,Ulrike; Koehler,Stefan; Silva,Ariovaldo J. da. |
| ABSTRACT This paper studied the effect of adding an enzyme (ellulose) on anaerobic digestion of maize silage. We compared materials at chopping lengths of 8 mm (MSL), 4mm (MSS) and natural size (Ms) under a mesophilic and discontinuous operation (batch process). Hence, we found the process to be significantly influenced by particle size. Moreover, the ellulose addition did not significantly impact biogas production after a 35-day digestion period. Ms and MSS displayed an improved response to all variables when compared with MSL and MSL+C, with significant differences. Studies on the refractory fraction at infinite time (R0) have demonstrated that the lowest values correspond to Ms and MSS (0.122 and 0.155, respectively). The Kinetic approach and the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ellulose; Silage; Biogas; Kinetics; Biodegradability. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162015000500951 |
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| Ahmed,Sibtain; Imdad,Syeda Sana; Jamil,Amer. |
| Xylanases assume special importance in the paper and pulp industry as they replace toxic chemicals such as chlorine and chlorine dioxide for developing eco-friendly processes. This study evaluated xylanases produced by two fungi, the mesophilic fungus Trichoderma harzianum and a thermophilic fungus Chaetomium thermophilum. Among the polymeric substrates studied for xylanase production by both the fungi, birch wood xylan was found to be the best inducer of xylanases. Xylanases induction was subject to glucose repression. Partially purified xylanases preparation from T. harzianum and C. thermophilum exhibited optimal activities at pH 5 and 6 and at 60ºC and 70ºC, respectively. The apparent Km and Vmax values for the partially purified xylanase from T.... |
| Tipo: Journal article |
Palavras-chave: C. thermophilum; Kinetics; T. harzianum; Xylanase. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582012000300003 |
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| Mukhtar,Hamid; Ikram-ul-Haq,. |
| We describe the simultaneous production of Bacillus subtilis based proteases and alpha amylase using a computer controlled laboratory scale 7.5 L batch bioreactor. The present strain is the first to be reported that concomitantly produces these two industrially important enzymes. The growth and sporulation of Bacillus subtilis was monitored and maximum production of alkaline protease and alpha amylase was found to coincide with maximum sporulation. Two types of proteases were detected in the fermentation broth; a neutral and an alkaline protease most active in a pH range of 7.0-8.0 and 8.0-10, respectively. Maximum production of proteases was observed at an incubation temperature of 37ºC while that of alpha amylase was observed at 40ºC. The optimum... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Simultaneous; Sporulation; Kinetics; Fermentation; Agitation. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822012000300033 |
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| Baron, Regis; Couedel, Marielle; Joret, Camille; Garen, Pierre; Truquet, Philippe; Masselin, Pierre; Bardouil, Michele; Lassus, Patrick. |
| A simple system was used to simulate the effect of alternating toxic (paralytic shellfish poisoning toxins) and non-toxic microalgal diets on oyster feeding behaviors and rates of toxin accumulation. These experimental conditions were meant to reflect, to some extent, the incoming and outgoing fluxes of toxic algae observed at the mouth of the Penze estuary (Northern Brittany, France). Physiological and toxicological parameters were estimated based oil fluorescence measurements recorded continuously at the outlet of each experimental tank, which contained a single oyster. Q(tox), this variable describes toxin uptake in oysters, it was used (instead of the toxin ingestion rate): i) in simple graphical analyses, ii) as well as in one- and two-compartment... |
| Tipo: Text |
Palavras-chave: Skeletonema costatum; Alexandrium minutum; Fluorescence; Modeling; Kinetics; Toxin uptake; Shellfish toxin; PSP. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1400.pdf |
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| Adona,P.R.; Leal,C.L.V.. |
| The effect of concentration and exposure period of bovine oocytes to butyrolactone I (BLI) on meiotic block and in vitro maturation (IVM) kinetics was studied. In experiment 1, all oocytes were at germinal vesicle stage (GV), after 6h in culture with 0, 50 and 100µM BLI. After 12h, all oocytes cultured with 50 and 100µM BLI remained in GV. After 24h, less oocytes were in GV with 50µM (82%) than with 100µM BLI (99%, P<0.05). In experiment 2, after 6h IVM, 93% of control oocytes (IVM only) were in GV, while treated oocytes (100µM BLI for 6, 12 or 24h prior to IVM) showed less oocytes in GV with increased exposure period to BLI prior to IVM (83 and 73%, for 6h and 12h, P<0.05). For a 24h inhibition, GV rates were similar to 12h (70%, P>0.05). After... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bovine; Meiosis; Oocyte; Butyrolactone I; Kinetics; Nuclear maturation. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352006000300011 |
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| Ruffine, Livio. |
| To gain in-depth understanding of natural gas hydrate behavior it is necessary to identify key parameters that affect their formation, distribution and destabilization within sediments. Hydrate formation kinetics in porous media is amongst the aspects which deserve important considerations as it may provide useful information on the formation history and the formation mechanisms of natural gas hydrate accumulations. Yet, it is at its early stage. In this paper, experiments on methane hydrate formation and dissociation in porous media are reported and discussed. The first part of this work is devoted to the investigation of the kinetics of methane hydrate formation within silica sand using a custom-design apparatus. The latter is suitable for investigating... |
| Tipo: Text |
Palavras-chave: Geologic matrices; Hydrate morphology; Kinetics; Methane hydrates; Novel apparatus. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00245/35580/34209.pdf |
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| Fagnani,Rafael; Schuck,Josiane; Botaro,Bruno Garcia; Santos,Fernando Cesar dos. |
| Abstract: The objective of this work was to evaluate the effect of the extended cold storage of raw milk on the kinetics of fermentation on yogurt production, as well as on the product’s microbiological and physicochemical properties during shelf life. Three treatments were evaluated: yogurts made with raw milk stored for 4, 72, and 168 hours. Kinetics of fermentation was assessed through the lactic acid production rate, growth rate of Streptococcus thermophilus and Lactobacillus bulgaricus, and time to reach pH 5.0 and 4.5. The physicochemical and microbiological characteristics of raw milk and yogurts were also analyzed during cold storage at 4°C. The microbial quality of raw milk was affected by the storage time of 168 hours, with a decreasing tendency... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lactobacillus bulgaricus; Streptococcus thermophilus; Fermentation; Kinetics; Psychrotrophs.. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2017000200104 |
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| Registros recuperados: 43 | |
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