The Experts below are selected from a list of 15972 Experts worldwide ranked by ideXlab platform
Francisco Valero - One of the best experts on this subject based on the ideXlab platform.
-
second and third generation biodiesel production with immobilised recombinant rhizopus oryzae lipase influence of the support substrate acidity and bioprocess scale up
Bioresource Technology, 2021Co-Authors: Josu Lopezfernandez, Maria Dolors Benaiges, Francisco ValeroAbstract:Abstract Rhizopus oryzae lipase immobilised onto differently functionalised polymethacrylate (Purolite®) and magnetite superparamagnetic supports was assessed as a catalyst for biodiesel production with pomace oil. The presence of surface hydrocarbon chains increased the operational stability of the Biocatalysts supported on Purolite® and superparamagnetic particles up to 9 and 2 times, respectively. By contrast, the presence of functional groups had no effect on the initial transesterification rate, which was twice higher with the lipase immobilised onto Purolite®. Also, functionalising Purolite® with epoxide and octadecyl groups led to the highest biodiesel and volumetric productivity. This Biocatalyst with other substrates including makauba, jatropha, waste cooking oil, and microbial oil, led to similar initial reaction rates. However, simply raising substrate acidity from 0.5 to 2% increased the operational stability of the Biocatalysts 15 times. A synergistic effect between acyl-acceptor concentration and substrate acidity was observed. The transesterification reaction was successfully scaled up to 50 mL.
-
biodiesel production from crude jatropha oil catalyzed by non commercial immobilized heterologous rhizopus oryzae and carica papaya lipases
Bioresource Technology, 2016Co-Authors: Jose Carlos Rodrigues, Francisco Valero, Albert Canet, Ivanna Rivera, Natalia M Osorio, Georgina Sandoval, Suzana FerreiradiasAbstract:The aim of this study was to evaluate the feasibility of biodiesel production by transesterification of Jatropha oil with methanol, catalyzed by non-commercial sn-1,3-regioselective lipases. Using these lipases, fatty acid methyl esters (FAME) and monoacylglycerols are produced, avoiding the formation of glycerol as byproduct. Heterologous Rhizopus oryzae lipase (rROL) immobilized on different synthetic resins and Carica papaya lipase (rCPL) immobilized on Lewatit VP OC 1600 were tested. Reactions were performed at 30°C, with seven stepwise methanol additions. For all Biocatalysts, 51-65% FAME (theoretical maximum=67%, w/w) was obtained after 4h transesterification. Stability tests were performed in 8 or 10 successive 4h-batches, either with or without rehydration of the Biocatalyst between each two consecutive batches. Activity loss was much faster when Biocatalysts were rehydrated. For rROL, half-life times varied from 16 to 579h. rROL on Lewatit VPOC 1600 was more stable than for rCPL on the same support.
Rafael C. Rodrigues - One of the best experts on this subject based on the ideXlab platform.
-
pectin lyase immobilization using the glutaraldehyde chemistry increases the enzyme operation range
Enzyme and Microbial Technology, 2020Co-Authors: Manuela P. Klein, Rafael C. Rodrigues, Lucas Dal Magro, Jakub F Kornecki, Roberto FernandezlafuenteAbstract:Abstract Pectin lyase (from Rohapect 10 L) was immobilized on glutaraldehyde supports at low ionic strength at pH 5, 6.5 or 8 and later incubated at pH 8 for 48 h. The activity recovery of the Biocatalysts versus pectin was quite low, under 10% for all of the immobilized Biocatalyst at 20 °C. However, a high stabilization was found when the enzyme was immobilized at pH 5, (e.g., the immobilized enzyme kept 83% of the activity when the free enzyme was fully inactivated (pH 4.8 and 55 °C in 5 h)). This Biocatalyst increased the activity versus pectin in an almost exponential way when temperature increased until reach the maximum temperature used in the study (90 °C), conditions where the free enzyme was almost inactive. The immobilized Biocatalyst was also active even at pH 9, where the free enzyme was fully inactive. This Biocatalyst could be reused for pectin hydrolysis 5 times for 72 h reaction cycles at 40 °C maintaining more than 90% of the initial activity.
-
Immobilization of pectinase on chitosan-magnetic particles: Influence of particle preparation protocol on enzyme properties for fruit juice clarification.
Biotechnology reports (Amsterdam Netherlands), 2019Co-Authors: Lucas Dal Magro, Kelly Silva De Moura, Betina Elys Backes, Eliana Weber De Menezes, Edilson Valmir Benvenutti, Sabrina Nicolodi, Manuela P. Klein, Roberto Fernandez-lafuente, Rafael C. RodriguesAbstract:Abstract Magnetic-chitosan particles were prepared following three different protocols enabling the preparation of particles with different sizes – nano (Nano-CMag, Micro (Micro-CMag) and Macro (Macro-CMag) – and used for pectinase immobilization and clarification of grape, apple and orange juices. The particle size had a great effect in the kinetic parameters, Nano-CMag Biocatalyst presented the highest Vmax value (78.95 mg. min−1), followed by Micro-CMag and Macro-CMag, with Vmax of 57.20 mg.min−1 and 46.03 mg.min−1, respectively. However, the highest thermal stability was achieved using Macro-CMag, that was 8 and 3-times more stable than Nano-CMag and Micro-CMag Biocatalysts, respectively. Pectinase immobilized on Macro-CMag kept 85% of its initial activity after 25 batch cycles in orange juice clarification. These results suggested that the chitosan magnetic Biocatalysts presented great potential application as clarifying catalysts for the fruit juice industry and the great importance of the chitosan particles preparation on the final Biocatalyst properties.
-
magnetic Biocatalysts of pectinase and cellulase synthesis and characterization of two preparations for application in grape juice clarification
International Journal of Biological Macromolecules, 2018Co-Authors: Lucas Dal Magro, Eliana Weber De Menezes, Edilson Valmir Benvenutti, Sabrina Nicolodi, Manuela P. Klein, Vitoria C C Silveira, Plinho Francisco Hertz, Rafael C. RodriguesAbstract:In the present study, we prepared two different magnetic Biocatalysts of pectinase and cellulase: carrier-free magnetic CLEAs (CLEA-MP*) and immobilization on glutaraldehyde-activated magnetite (Enz-Glu-MP*). The Biocatalysts were compared to their magnetic properties, immobilization parameters, stability and grape juice clarification. Enz-Glu-MP* presented higher magnetic properties than CLEA-MP*, whereas this presented higher surface area and pore volume. The KM of the enzyme immobilized on Enz-Glu-MP* was 25.65mM, lower in comparison to the CLEA-MP* (33.83mM). On the other hand, CLEA-MP* was the most active and stable Biocatalyst, presenting higher recovered activity (33.4% of cellulase), higher thermal stability (2.39 stabilization factor) and improved reusability (8cycles). The integration of magnetic technology with enzymatic immobilization emerges as a possibility to increase the recover and reuse of Biocatalysts for application in juice technology.
-
immobilization of lipase b from candida antarctica on porous styrene divinylbenzene beads improves butyl acetate synthesis
Biotechnology Progress, 2012Co-Authors: Natalia G Graebin, Roberto Fernandezlafuente, Andrea B Martins, Andre Soibelmann Glock Lorenzoni, Cristina Garciagalan, Marco Antonio Zachia Ayub, Rafael C. RodriguesAbstract:A new Biocatalyst of lipase B from Candida antarctica (MCI-CALB) immobilized on styrene–divinylbenzene beads (MCI GEL CHP20P) was compared with the commercial Novozym 435 (immobilized lipase) in terms of their performances as Biocatalysts for the esterification of acetic acid and n-butanol. The effects of experimental conditions on reaction rates differed for each Biocatalyst, showing different optimal values for water content, temperature, and substrate molar ratio. MCI-CALB could be used at higher acid concentrations, up to 0.5 M, while Novozym 435 became inactivated at these acid concentrations. Although Novozym 435 exhibited 30% higher initial activity than MCI-CALB for the butyl acetate synthesis, the reaction course was much more linear using the new preparation, meaning that the MCI-CALB allows for higher productivities per cycle. Both preparations produced around 90% of yield conversions after only 2 h of reaction, using 10% (mass fraction) of enzyme. However, the main advantage of the new Biocatalyst was the superior performance during reuse. While Novozym 435 was fully inactivated after only two batches, MCI-CALB could be reused for six consecutive cycles without any washings and keeping around 70% of its initial activity. It is proposed that this effect is due to the higher hydrophobicity of the new support, which does not retain water or acid in the enzyme environment. MCI-CALB has shown to be a very promising Biocatalyst for the esterification of small-molecule acids and alcohols. © 2012 American Institute of Chemical Engineers Biotechnol. Prog.,, 2012
Roberto Fernandezlafuente - One of the best experts on this subject based on the ideXlab platform.
-
pectin lyase immobilization using the glutaraldehyde chemistry increases the enzyme operation range
Enzyme and Microbial Technology, 2020Co-Authors: Manuela P. Klein, Rafael C. Rodrigues, Lucas Dal Magro, Jakub F Kornecki, Roberto FernandezlafuenteAbstract:Abstract Pectin lyase (from Rohapect 10 L) was immobilized on glutaraldehyde supports at low ionic strength at pH 5, 6.5 or 8 and later incubated at pH 8 for 48 h. The activity recovery of the Biocatalysts versus pectin was quite low, under 10% for all of the immobilized Biocatalyst at 20 °C. However, a high stabilization was found when the enzyme was immobilized at pH 5, (e.g., the immobilized enzyme kept 83% of the activity when the free enzyme was fully inactivated (pH 4.8 and 55 °C in 5 h)). This Biocatalyst increased the activity versus pectin in an almost exponential way when temperature increased until reach the maximum temperature used in the study (90 °C), conditions where the free enzyme was almost inactive. The immobilized Biocatalyst was also active even at pH 9, where the free enzyme was fully inactive. This Biocatalyst could be reused for pectin hydrolysis 5 times for 72 h reaction cycles at 40 °C maintaining more than 90% of the initial activity.
-
amination of ficin extract to improve its immobilization on glyoxyl agarose improved stability and activity versus casein
International Journal of Biological Macromolecules, 2019Co-Authors: Elhocine Siar, Roberto Morellonsterling, Mohammed Nasreddine Zidoune, Roberto FernandezlafuenteAbstract:Abstract Ficin extract has been aminated using ethylenediamine and carbodiimide to transform all exposed carboxylic groups into amino groups, retaining around 80% of activity versus benzoyl- d , l -arginine p -nitroanilide hydrochloride (BANA) and 90% versus casein. This aminated enzyme was then immobilized on glyoxyl agarose beads. After optimization of the immobilization protocol (immobilization at pH 10 for just 1 h), the new Biocatalyst was compared to that obtained using the non-aminated enzyme. Activity versus BANA was lower, but was higher versus casein. The new Biocatalyst was more stable than the reference mainly at pH 7. The new Biocatalyst permitted to have a more linear course and a higher hydrolysis yield of casein at 75 °C. Moreover, the activity of the new preparations was significantly higher than the reference or the free enzyme in 8 M urea, at pH 7 and 55 °C. The enzyme in an overloaded Biocatalyst exhibited a much higher specific activity versus casein (75% of the low loaded Biocatalysts) than the non-aminated enzyme (only 30%), suggesting a more appropriate enzyme orientation that decreased steric hindrances. Finally, the enzyme was reused for 5 cycles of casein hydrolysis at 40 °C and pH 7 without any decrease in enzyme activity.
-
synthesis of benzyl acetate catalyzed by lipase immobilized in nontoxic chitosan polyphosphate beads
Molecules, 2017Co-Authors: Ana D Q Melo, Telma L. G. Lemos, Roberto Fernandezlafuente, Jose Dos C S Santos, Francisco Silva, Francisco Dias A FilhoAbstract:Enzymes serve as Biocatalysts for innumerable important reactions, however, their application has limitations, which can in many cases be overcome by using appropriate immobilization strategies. Here, a new support for immobilizing enzymes is proposed. This hybrid organic-inorganic support is composed of chitosan—a natural, nontoxic, biodegradable, and edible biopolymer—and sodium polyphosphate as the inorganic component. Lipase B from Candida antarctica (CALB) was immobilized on microspheres by encapsulation using these polymers. The characterization of the composites (by infrared spectroscopy, thermogravimetric analysis, and confocal Raman microscopy) confirmed the hybrid nature of the support, whose external part consisted of polyphosphate and core was composed of chitosan. The immobilized enzyme had the following advantages: possibility of enzyme reuse, easy Biocatalyst recovery, increased resistance to variations in temperature (activity declined from 60 °C and the enzyme was inactivated at 80 °C), and increased catalytic activity in the transesterification reactions. The encapsulated enzymes were utilized as Biocatalysts for transesterification reactions to produce the compound responsible for the aroma of jasmine.
-
effect of immobilization rate and enzyme crowding on enzyme stability under different conditions the case of lipase from thermomyces lanuginosus immobilized on octyl agarose beads
Process Biochemistry, 2017Co-Authors: Hadjer Zaak, Jakub F Kornecki, Jose J Virgenortiz, Elhocine Siar, Laura Fernandezlopez, Sara G Pedrero, Roberto FernandezlafuenteAbstract:Abstract Lipase from Thermomyces lanuginosus (TLL) was immobilized on octyl agarose (OC). Three different TLL-OC Biocatalysts were prepared: one lowly loaded using a low enzyme concentration, one fully loaded using a low enzyme concentrations, and a final one using a large excess of enzyme at a higher concentration. The activities after immobilization increased (180%), although diffusion limitations reduced the hyperactivation of the fully loaded preparations (140%). The stabilities of both preparations using low enzyme concentrations were similar under all studied conditions discounting the diffusional limitations of the Biocatalyst. However, the Biocatalyst prepared using a large concentration of enzyme was less stable that the other preparations at pH 7.0, more stable at pH 5.0 and with a similar stability at pH 9.0. Adding 3 M NaCl, the stability of the fully loaded preparations significantly increased; while the lowly loaded preparation slightly improved enzyme stability. This produced that the Biocatalyst prepared under using high enzyme concentration become significantly more stable than the other two TLL preparations. Glycerin increased immobilized TLL stability, in this case all OC-TLL preparations became with similar stabilities. Results show that the TLL concentration during immobilization may greatly affect TLL properties, perhaps due to altering enzyme packing.
-
relevance of substrates and products on the desorption of lipases physically adsorbed on hydrophobic supports
Enzyme and Microbial Technology, 2017Co-Authors: Jose J Virgenortiz, Daniela B Hirata, Veymar G Taciaspascacio, Beatriz Torrestianasanchez, Arnulfo Rosalesquintero, Roberto FernandezlafuenteAbstract:Abstract Lipase B from Candida antarctica (CALB) has been physically immobilized on octyl-agarose via interfacial activation. The incubation of the enzyme in 80% ethanol at pH 5 and 25 °C has not significant effect on enzyme activity. Moreover, the hydrolysis of 100 mM tributyrin catalyzed by this Biocatalyst exhibited a quite linear reaction course. However, a new cycle of tributyrin hydrolysis showed a drastic drop in the activity. SDS-PAGE gels of the supernatant and the Biocatalyst showed a significant enzyme desorption after the reaction. Similar results could be appreciated using triacetin or sunflower oil, while using 300 mM methyl phenyl acetate, butyl butyrate or ethyl butyrate most enzyme molecules remained immobilized. The results show that the detergent properties of some reaction products increase the enzyme release from the hydrophobic support, and this problem increased if the concentration of the reactants increased. Using 500 mM tributyrin, even in fully aqueous medium, some enzyme desorption from the support may be observed. Thus, the results show a limitation of this kind of Biocatalysts that should be considered in the selection of an industrial lipase Biocatalyst.
Rafael Luque - One of the best experts on this subject based on the ideXlab platform.
-
sol gel immobilisation of lipases towards active and stable Biocatalysts for the esterification of valeric acid
Molecules, 2018Co-Authors: Soledad Cebriangarcia, Alina M Balu, Rafael Luque, Araceli GarciaAbstract:Alkyl esters are high added value products useful in a wide range of industrial sectors. A methodology based on a simple sol-gel approach (biosilicification) is herein proposed to encapsulate enzymes in order to design highly active and stable Biocatalysts. Their performance was assessed through the optimization of valeric acid esterification evaluating the effect of different parameters (Biocatalyst load, presence of water, reaction temperature and stirring rate) in different alcoholic media, and comparing two different methodologies: conventional heating and microwave irradiation. Ethyl valerate yields were in the 80⁻85% range under optimum conditions (15 min, 12% m/v Biocatalyst, molar ratio 1:2 of valeric acid to alcohol). Comparatively, the Biocatalysts were slightly deactivated under microwave irradiation due to enzyme denaturalisation. Biocatalyst reuse was attempted to prove that good reusability of these sol-gel immobilised enzymes could be achieved under conventional heating.
Hideki Fukuda - One of the best experts on this subject based on the ideXlab platform.
-
Development of an Aspergillus oryzae whole-cell Biocatalyst coexpressing triglyceride and partial glyceride lipases for biodiesel production.
Bioresource technology, 2011Co-Authors: Daisuke Adachi, Shinji Hama, Takao Numata, Kazunori Nakashima, Chiaki Ogino, Hideki Fukuda, Akihiko KondoAbstract:An Aspergillus oryzae whole-cell Biocatalyst which coexpresses Fusarium heterosporum lipase (FHL) and mono- and di-acylglycerol lipase B (mdlB) in the same cell has been developed to improve biodiesel production. By screening a number of transformants, the best strain was obtained when FHL gene was integrated into A. oryzae chromosome using sC selection marker while mdlB was integrated using niaD selection marker. The reaction system using the lipase-coexpressing whole-cells was found to be superior in biodiesel production to others such as lipase-mixing and two-step reactions, affording the highest reaction rate and the highest ME content (98%). Moreover, an ME content of more than 90% was maintained during 10 repeated batch cycles. The whole-cell Biocatalyst developed in this work would be promising Biocatalysts for efficient biodiesel production.
-
immobilized recombinant aspergillus oryzae expressing heterologous lipase an efficient whole cell Biocatalyst for enantioselective transesterification in non aqueous medium
Journal of Molecular Catalysis B-enzymatic, 2007Co-Authors: Sriappareddy Tamalampudi, Shinji Hama, Akihiko Kondo, Takanori Tanino, Mahabubur Rahman Talukder, Hideki FukudaAbstract:Organic esters are used in various industries such as perfumery, flavour and pharmaceutical intermediates. The use of Biocatalysts for esterification and transesterification reaction under ambient reaction conditions gives better products for use in flavour and fragrance industries. In the current study, enantioselective transesterification reaction was developed by using recombinant Aspergillus oryzae whole-cell Biocatalyst expressing lipase-encoding gene from Candida antarctica. The recombinant fungal cells were immobilized on Biomass Support Particles (BSPs) to facilitate the reusability of whole-cell Biocatalyst. The immobilized CALB expressing whole-cell Biocatalyst was used for the optical resolution of (RS)-1-phenylethanol by enantioselective transesterification with vinyl acetate as acyl donor. The activity of the whole-cell Biocatalyst was optimized and compared with the other whole-Biocatalysts E. coli displaying CALB, S. cerevisiae displaying ROL and A. oryzae whole-cell Biocatalyst expressing tglA lipase. The initial activity of immobilized CALB expressing A. oryzae was at least 15-folds higher than that of A. oryzae expressing tglA lipase. The maximum yield of (R)-1-phenylethyl acetate reached 88.1% with an enantiomeric excess (ee) of >99% after 3.5 h reaction, while tglA lipase expressing A. oryzae showed 90% yield and 95% ee after 48 h. The recombinant A. oryzae retained its activity in hexane, heptane, toluene, cyclohexane and octane. Moreover, whole-cell Biocatalyst maintained its activity for more than 15 batch reaction cycles. Current study demonstrated the applicability of recombinant whole-cell Biocatalyst to bioconversion process in non-aqueous medium.