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Ferraz L.I.R.,URI Integrated Regional University Brazil | Possebom G.,URI Integrated Regional University Brazil | Alvez E.V.,URI Integrated Regional University Brazil | Cansian R.L.,URI Integrated Regional University Brazil | And 3 more authors.
Biocatalysis and Agricultural Biotechnology | Year: 2015

This work relates the maximization of geranyl propionate production by esterification in solvent-free system using a lipase extract from Penicillium crustosum. A sequencial strategy of experimental design was carried out followed by a kinetic study. The study of reuse of the non-commercial immobilized enzymatic extract was also carried out. The operating conditions that maximized geranyl propionate production were determined to be 60 1C, geraniol to propionic acid mole ratio of 5:1, 150 rpm and 50 wt% of lipase extract, resulting in a conversion of about 53%. A kinetic study was performed and the results allow to conclude that an excess of alcohol (alcohol to acid mole ratio of 5:1), relatively low enzyme concentration (50 wt%) and 40 1C afforded good conversions after 50 min. The relative activity decreased along the reuse, retaining around 50% of the same after four cycles. The decrease in the activity of the immobilized extract was accompanied by a drop in geranyl propionate conversions. New experimental data on enzymatic esterification of geraniol and propionic acid for geranyl propionate production are reported in this work, showing a promising perspective of using low cost biocatalysts to overcome the well-known drawbacks of the chemical-catalyzed route. © 2014 Elsevier Ltd. Source

Rigoli Ferraz L.,URI Integrated Regional University Brazil | Santos de Oliveira D.D.,URI Integrated Regional University Brazil | Fernandes Silva M.,URI Integrated Regional University Brazil | Rigo E.,URI Integrated Regional University Brazil | And 5 more authors.
Biocatalysis and Agricultural Biotechnology | Year: 2012

Lipases produced by a newly isolated Sporidiobolus ruberrimus strain have potential catalytic ability for esterification reactions. Lipase activities of about 130.1. U/g, 164.2. U/g and 189.5. U/g were obtained using soybean meal, sugarcane bagasse and rice meal as substrates, respectively. The partial characterization of the crude extracts showed that the evaluated lipases presented, in general, more specificity to short chain alcohols and fatty acids. The extracts presented higher relative activities when stored at room temperature compared to the storage at 4 and -10 °C. Lipases showed higher activities at memories of pH around neutrality (6.5) and about 40 °C. © 2012 Elsevier Ltd. Source

Coghetto C.C.,URI Integrated Regional University Brazil | Scherer R.P.,URI Integrated Regional University Brazil | Silva M.F.,URI Integrated Regional University Brazil | Golunski S.,URI Integrated Regional University Brazil | And 5 more authors.
Biocatalysis and Agricultural Biotechnology | Year: 2012

The objective of this study was to investigate the process of immobilization of inulinases using natural montmorillonite as inorganic support. The enzyme to buffer ratio of 3:10 and 10min of immobilization led to the highest specific activity, 375.07U/mg protein. The immobilized inulinase kept its activity after 1968h under storage at low temperatures and after 456-1826h at high temperatures. The pH value of 3.5 led to the highest specific activity. K m values of 1.46 and 0.38mM, and v max of 0.2487 and 0.2396mol/Lmin, were obtained, respectively, for sucrose and inulin. © 2012 Elsevier Ltd. Source

Silva M.F.,URI Integrated Regional University Brazil | Rigo D.,URI Integrated Regional University Brazil | Mossi V.,URI Integrated Regional University Brazil | Dallago R.M.,URI Integrated Regional University Brazil | And 6 more authors.
Food and Bioproducts Processing | Year: 2013

The objective of this work was to evaluate the stability of the activity of commercial inulinase from Aspergillus niger immobilized in polyurethane foam. The activity of the enzyme was measured in the hydrolysis reaction of both sucrose and inulin at 50°C and pH 5.5. The enzyme reuse was evaluated during 59 days and 29 reuse cycles. The inulinase immobilized in polyurethane kept 49.7% and 49.4% of its initial activity during 1008 h and 24 reuse cycles for sucrose and inulin, respectively. In this work, enzyme immobilization was accomplished together with the formation of the polyurethane foam, which is an interesting characteristic, differing from several works found in the literature. Taking into account the promising results obtained, the low cost of the immobilization support employed and the whole technique developed, this work may comprise an innovative contribution. © 2012 The Institution of Chemical Engineers. Source

De Oliveira Kuhn G.,URI Integrated Regional University Brazil | Rosa C.D.,URI Integrated Regional University Brazil | Silva M.F.,URI Integrated Regional University Brazil | Treichel H.,University Federal Da Fronteira Sul Campus Of Erechim | And 2 more authors.
Applied Biochemistry and Biotechnology | Year: 2013

Commercial inulinase from Aspergillus niger was immobilized in montmorillonite and then treated in pressurized propane and liquefied petroleum gas (LPG). Firstly, the effects of system pressure, exposure time, and depressurization rate, using propane and LPG, on enzymatic activity were evaluated through central composite design 23. Residual activities of 145.1 and 148.5 % were observed for LPG (30 bar, 6 h, and depressurization rate of 20 barmin-1) and propane (270 bar, 1 h, and depressurization rate of 100 barmin-1), respectively. The catalysts treated at these conditions in both fluids were then used for the production of fructooligosaccharides (FOS) using sucrose and inulin as substrates in aqueous and organic systems. The main objective of this step was to evaluate the yield and productivity in FOS, using alternatives for enhancing enzyme activity by means of pressurized fluids and also using low-cost supports for enzyme immobilization, aiming at obtaining a stable biocatalyst to be used for synthesis reactions. Yields of 18 % were achieved using sucrose as substrate in aqueous medium, showing the potential of this procedure, hence suggesting a further optimization step to increase the process yield. © Springer Science+Business Media New York 2013. Source

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