First International Conference on
Unconventional Catalysis, Reactors and Applications

Zaragoza-Spain, 16-18 October 2019
11:40   Unconventional catalyst synthesis and manufacturing methods 4
Chair: Sofia Calero
11:40
20 mins

#4
PROBLEMS AND ADVANTAGES OF ENZYME COIMMOBILIZATION: SOLUTIONS TO DIFFERENT ENZYMES STABILITIES
Sara Arana-Peña, Carmen Mendez-Sanchez, Nathalia Rios, Juan J. Virgen-Ortíz, Laura Fernandez-Lopez, Hadjer Zaak, Roberto Fernandez-Lafuente (presenter: Roberto Fernandez-Lafuente)
Abstract: The interest of coimmobilization of enzymes is increasing everyday [1-2]. In cascade reactions, it avoids the lag-time that produces the use of enzymes independently immobilized in different particles [2]. In some cases, it is fully compulsory to prevent the destruction of one of the first enzyme product [3]. However, there some problems directly related to the coimmobilization of two enzymes in one particle [4]. First, it is possible that the best immobilization protocol differs from one enzyme to the other, making necessary to reach compromise solutions. This makes that immobilization cannot be fully utilized to get improved preparations of both enzymes [4]. Second, after inactivation of the least stable enzyme, both enzymes are discarded, even if the other enzyme remains fully active. Here we presented some solutions to these problems, useful when one enzyme may be stabilized via immobilization, while the other enzyme cannot, and the first immobilized/stabilized enzyme is much more stable than the other enzyme [5].
12:00
20 mins

#35
NEW IMMOBILIZATION PROTOCOLS AND EXTREMELLY DRY MEDIUM TO SPEED UP THE PRODUCTION OF PHOSPHOLIPIDS RICH IN CLA WITH PHOSPHOLIPASE LECITASE ULTRA
Cristina Otero, Carlos Manuel Verdasco-Martín, Carlos Corchado-Lopo, Roberto Fernández-Lafuente (presenter: Cristina Otero)
Abstract: Structured phospholipids (SPL) and lipids rich in conjugated linolenic acid (CLA) have important beneficial health effects.1 Synthesis of SPL has been greatly speeded (12 times, from 24h to 2h total reaction time) using new immobilized derivatives of phospholipase A1 Lecitase Ultra2. Also, side-hydrolysis, typically reducing SPL yields to 3-30%, has been avoided (<0.5%) using precise systems for extreme PL dehydration. Fig. 1. Acidolysis of PC catalyzed by OM octadecyl methacrylate Purolite derivative, using dried PC (279 ± 4 mg water/Kg PC). F.A.: fatty acids. References 1. Verdasco-Martín, C. M. et al. Food Chemistry, 2018, 245, 39-46. 2. Tacias-Pascacio, V. G. et al. Fuel, 2017, 200, 1-10.
12:20
20 mins

#11
ENZYMATIC MONOLITHIC REACTORS FOR MICROPOLLUTANTS DEGRADATION
Sher Ahmad, Wassim Sebai, Anne Galarneau, Nicolas Brun, Marie-Pierre Belleville, Jose Sanchez-Marcano (presenter: Jose Sanchez Marcano)
Abstract: Enzymatic membrane reactors with grafted laccases have been reported to degrade some pharmaceuticals [1]. However, the process efficiency is limited by the low capacity of enzyme immobilization on membranes. Silica monoliths with hierarchical macro-/mesoporosity (20 µm, 20 nm) and high surface area (370 m²/g) are supports able to improve the concentration of immobilized enzymes. Monoliths obtained via a combination of sol-gel process and spinodal decomposition (0.6 diameter and 0.5 or 3 cm length) were cladded with a Teflon heat shrinkable gain connected to stainless-steel tubing in order to form tubular reactors. Laccase (Trametes versicolor) was immobilized in monoliths by covalent grafting and adsorption. Tetracycline (TC) oxidation was tested as model reaction by flowing continuously the solutions through the porosity of activated monoliths in continuous flow configuration. Indeed, the substrates were forced to be in contact with the entire activated surface (“flow through bio-reactor” configuration) allowing the decrease of diffusion limitations and improving the contact between the substrates and the biocatalyst. First results showed that these active monoliths are able to degrade 40-55 % of TC (8 mg.L-1) in 10 h at pH 7 and room temperature. This study shows that this new kind of bioreactor configuration is promising for the depollution of wastewaters presenting the advantages of enzyme-support binding without leaching and loss of activity.
12:40
20 mins

#59
CATALYTIC AND ELECTRON CONDUCTING CARBON NANOTUBE-REINFORCED LYSOZYME CRYSTALS
Rafael Contreras-Montoya, Guillermo Escolano, Subhasis Roy, Modesto T. López-López, José M. Delgado-López, Juan M. Cuerva, Juan J. Díaz-Mochón, Nurit Ashkenasy, José A. Gavira, Luis Álvarez de Cienfuegos (presenter: Rafael Contreras-Montoya)
Abstract: We have produced and characterized novel reinforced cross-linked lysozyme crystals containing homogeneous dispersions of single-walled carbon nanotubes (SWCNTs). The incorporation of SWCNTs inside lysozyme crystals gives rise to reinforced hybrid materials with tunable mechanical strength and electronic conductivity, while preserving the crystal-quality and morphology. Furthermore, the extraordinary stability of these crystals makes their catalytic activity increase with increasing temperature, being very active even above the denaturation temperature of lysozyme. To obtain these crystals we have developed a new protocol based on the in situ crystallization of lysozyme in hybrid SWCNTs-peptide hydrogels. These peptide hydrogels have been able to homogeneously dispersed hydrophobic SWCNTs allowing first, the crystallization of the model enzyme lysozyme and secondly, transferring the new properties of the inorganic component to the crystals. Taken together, these hybrid crystals represent a notorious example of the versatility of proteins as biological substrates in the generation of novel functional materials and pave the way to develop novel bioorthogonal catalysts by doping the structures with abiotic metal catalyst.