150 research outputs found
Production of a biodiesel-like biofuel without glycerol generation, by using Novozym 435, an immobilized Candida antarctica lipase
Background: Novozym 435, a commercial lipase from Candida antarctica, recombinant, expressed in Aspergillus niger,
immobilized on macroporous acrylic resin, has been already described in the obtention of biodiesel. It is here evaluated
in the production of a new biofuel that integrates the glycerol as monoglyceride (MG) together with two fatty acid
ethyl esters (FAEE) molecules by the application of 1,3-selective lipases in the ethanolysis reaction of sunflower oil.
Results: Response surface methodology (RSM) is employed to estimate the effects of main reaction. Optimum
conditions for the viscosity, selectivity, and conversion were determined using a multifactorial design of
experiments with three factors run by the software Stat Graphics version XV.I. The selected experimental
parameters were reaction temperature, oil/ethanol ratio and alkaline environment. On the basis of RSM analysis,
the optimum conditions for synthesis were 1/6 oil/EtOH molar ratio, 30°C, and 12.5 μl of NaOH 10 N aqueous
solutions, higher stirring than 300 rpm, for 2 h and 0.5 g of biocatalyst.
Conclusions: These obtained results have proven a very good efficiency of the biocatalyst in the studied selective
process. Furthermore, it was allowed sixteen times the successive reuse of the biocatalyst with good performanc
Biocatalytic behaviour of immobilized Rhizopus oryzae lipase in the 1,3-selective ethanolysis of sunflower oil to obtain a biofuel similar to biodiesel
A new biofuel similar to biodiesel was obtained in the 1,3-selective transesterification reaction of sunflower oil with ethanol using as biocatalyst a Rhizopus oryzae lipase (ROL) immobilized on Sepiolite, an inorganic support. The studied lipase was a low cost powdered enzyme preparation, Biolipase-R, from Biocon-Spain, a multipurpose additive used in food industry. In this respect, it is developed a study to optimize the immobilization procedure of these lipases on Sepiolite. Covalent immobilization was achieved by the development of an inorganic-organic hybrid linker formed by a functionalized hydrocarbon chain with a pendant benzaldehyde, bonded to the AlPO4 support surface. Thus, the covalent immobilization of lipases on amorphous AlPO 4/sepiolite (20/80 wt %) support was evaluated by using two different linkers (p-hydroxybenzaldehyde and benzylamine-terephthalic aldehyde, respectively). Besides, the catalytic behavior of lipases after physical adsorption on the demineralized sepiolite was also evaluated. Obtained results indicated that covalent immobilization with the p-hydroxybenzaldehyde linker gave the best biocatalytic behavior. Thus, this covalently immobilized lipase showed a remarkable stability as well as an excellent capacity of reutilization (more than five successive reuses) without a significant loss of its initial catalytic activity. This could allow a more efficient fabrication of biodiesel minimizing the glycerol waste production. © 2014 by the authors.Grants from the Spanish Ministry of Economy and Competitiveness (Project ENE 2011-27017),
Spanish Ministry of Education and Science (Projects CTQ2010-18126 and CTQ2011-28954-C02-02),
FEDER funds and Junta de Andalucía FQM 0191, PO8-RMN-03515 and P11-TEP-7723 are gratefully
acknowledged by the authors. We are also gratefully to Biocon®-Spain, for the kindly supply of the
BIOLIPASE-R®. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)Peer Reviewe
Obtención de un biocombustible que integra la glicerina empleando como catalizador heterogéneo KF soportado
A Biofuel Similar to Biodiesel Obtained by Using a Lipase from Rhizopus oryzae, Optimized by Response Surface Methodology
A new biodiesel-like biofuel is obtained by the enzymatic ethanolysis reaction
of sunflower oil with ethanol, in free solvent media, by using BIOLIPASE-R, a
multipurpose alimentary additive from Biocon®-Spain that is a low cost lipase from a strain
of Rhizopus oryzae. This biofuel is composed by two parts of fatty acid ethyl esters
(FAEE) and one of monoglyceride (MG), which in this form integrates glycerol, through
the application of the 1,3-selective lipases. Thus, this process minimizes waste generation
and maximizes the efficiency of the process because no residual glycerol is produced.
Response surface methodology (RSM) is employed to evaluate the main reaction
parameters (reaction temperature, oil/ethanol ratio and pH) on the sunflower oil
conversion. Water content and amount of lipase were also previously investigated.
Regarding the results, we found that it operates optimally with a water content of the
reaction medium of 0.15%, 0.05%–0.1% lipase by weight relative to the weight of oil used, 20 °C, volume ratio (mL/mL) oil/ethanol 12/3.5 and pH 12 (by addition of 50 μL of 10 N
NaOH solution). These results have proven a very good efficiency of the biocatalyst in the
studied selective process
Biocatalytic Behaviour of Immobilized Rhizopus oryzae Lipase in the 1,3-Selective Ethanolysis of Sunflower Oil to Obtain a Biofuel Similar to Biodiesel
A new biofuel similar to biodiesel was obtained in the 1,3-selective
transesterification reaction of sunflower oil with ethanol using as biocatalyst a Rhizopus
oryzae lipase (ROL) immobilized on Sepiolite, an inorganic support. The studied lipase
was a low cost powdered enzyme preparation, Biolipase-R, from Biocon-Spain, a
multipurpose additive used in food industry. In this respect, it is developed a study to
optimize the immobilization procedure of these lipases on Sepiolite. Covalent
immobilization was achieved by the development of an inorganic-organic hybrid linker
formed by a functionalized hydrocarbon chain with a pendant benzaldehyde, bonded to the
AlPO4 support surface. Thus, the covalent immobilization of lipases on amorphous
AlPO4/sepiolite (20/80 wt %) support was evaluated by using two different linkers
(p-hydroxybenzaldehyde and benzylamine-terephthalic aldehyde, respectively). Besides,
the catalytic behavior of lipases after physical adsorption on the demineralized sepiolite
was also evaluated. Obtained results indicated that covalent immobilization with the
p-hydroxybenzaldehyde linker gave the best biocatalytic behavior. Thus, this covalently immobilized lipase showed a remarkable stability as well as an excellent capacity of
reutilization (more than five successive reuses) without a significant loss of its initial
catalytic activity. This could allow a more efficient fabrication of biodiesel minimizing the
glycerol waste productio
Síntesis de un nuevo biocombustible que integra la glicerina empleando óxido de calcio como catalizador heterogéneo
New Biofuel Integrating Glycerol into Its Composition Through the Use of Covalent Immobilized Pig Pancreatic Lipase
By using 1,3-specific Pig Pancreatic lipase (EC 3.1.1.3 or PPL), covalently
immobilized on AlPO4/Sepiolite support as biocatalyst, a new second-generation biodiesel
was obtained in the transesterification reaction of sunflower oil with ethanol and other
alcohols of low molecular weight. The resulting biofuel is composed of fatty acid ethyl
esters and monoglycerides (FAEE/MG) blended in a molar relation 2/1. This novel
product, which integrates glycerol as monoacylglycerols (MG) into the biofuel
composition, has similar physicochemical properties compared to those of conventional
biodiesel and also avoids the removal step of this by-product. The biocatalyst was found to
be strongly fixed to the inorganic support (75%). Nevertheless, the efficiency of the
immobilized enzyme was reduced to half (49.1%) compared to that of the free PPL. The
immobilized enzyme showed a remarkable stability as well as a great reusability (more
than 40 successive reuses) without a significant loss of its initial catalytic activity.
Immobilized and free enzymes exhibited different reaction mechanisms, according to the different results in the Arrhenius parameters (Ln A and Ea). However, the use of supported
PPL was found to be very suitable for the repetitive production of biofuel due to its facile
recyclability from the reaction mixture
Biofuel that Keeps Glycerol as Monoglyceride by 1,3-Selective Ethanolysis with Pig Pancreatic Lipase Covalently Immobilized on AlPO4 Support
By using pig pancreatic lipase (EC 3.1.1.3 or PPL) as a biocatalyst, covalently
immobilized on amorphous AlPO4 support, a new second generation biodiesel was
obtained in the transesterification reaction of sunflower oil with ethanol. The resulting
biofuel is composed of fatty acid ethyl esters and monoglycerides (FAEE/MG) blended in
a 2:1 molar ratio. This novel product, which integrates glycerol as monoacylglycerols
(MG) into the biofuels composition, has similar physicochemical properties as
conventional biodiesel and also avoids the removal step of the by-product by washing of
the biodiesel with water. Immobilization of PPL was achieved by covalent attachment of
the ε-amino group of the lysine residues of PPL with the aldehyde groups of
p-hydroxybenzaldehyde linked on a hybrid organic-inorganic functionalized AlPO4
surface. With this procedure, the PPL biocatalyst was strongly fixed to the inorganic
support surface (94.3%). Nevertheless, the efficiency of the immobilized enzyme was
relatively lower compared to that of the free PPL, but it showed a remarkable stability as
well as a great capacity of reutilization (25 reuses) without a significant loss of its initial catalytic activity. Therefore, this enzymatic method allows the production of a biodiesel
which integrates the glycerol, allows a more efficient fabrication method and minimizes
the waste production as compared to the conventional alkali-catalyzed process
Obtención de biocombustibles que integran la glicerina mediante la aplicación de lipasas silvestres
An integrin-targeted photoactivatable Pt(IV) complex as a selective anticancer pro-drug: synthesis and photoactivation studies
A new anticancer agent based on the conjugation of a photoactivatable Pt(IV) pro-drug to a cyclic RGD-containing peptide is described. Upon visible light irradiation, phototoxicity was induced preferentially in SK-MEL-28 melanoma cancer cells overexpressing alphaVbeta3 integrin compared to control DU-145 human prostate carcinoma cells
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