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231 results on '"Molina-Grima, Emilio"'

1. Role of dynamic surface tension of silicone polyether surfactant-based silicone coatings on protein adsorption: An insight on the ‘ambiguous’ interfacial properties of Fouling Release Coatings

Author

Soriano-Jerez, Yolanda, Gourlaouen, Elliot, Zeriouh, Ouassim, Cerón-García, María del Carmen, Arrabal-Campos, Francisco M., Ruiz-Martínez, Cristina, Fernández, Ignacio, Gallardo-Rodríguez, Juan José, García-Camacho, Francisco, Molina-Grima, Emilio, and Bressy, Christine

Published
2024
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29. Long-lasting biofouling formation on transparent fouling-release coatings for the construction of efficient closed photobioreactors

Author

Soriano-Jerez, Yolanda, García-Abad, Lucía, del Carmen Cerón-García, María, Gallardo-Rodríguez, Juan José, Bressy, Christine, García-Camacho, Francisco, and Molina-Grima, Emilio

Abstract

In order to build an efficient closed-photobioreactor (PBR) in which biofouling formation is avoided, a non-toxic coating with high transparency is required, which can be applied to the interior surface of the PBR walls. Nowadays, amphiphilic copolymers are being used to inhibit microorganism adhesion, so poly(dimethylsiloxane)-based coatings mixed with poly(ethylene glycol)-based copolymers could be a good option. The 7 poly(dimethylsiloxane)-based coatings tested in this work contained 4% w/w of poly(ethylene glycol)-based copolymers. All were a good alternative to glass because they presented lower cell adhesion. However, the DBE-311 copolymer proved the best option due to its very low cell adhesion and high transmittance. Furthermore, XDLVO theory indicates that these coatings should have no cell adhesion at time 0 since they create a very high-energy barrier that microalgae cells cannot overcome. Nevertheless, this theory also shows that their surface properties change over time, making cell adhesion possible on all coatings after 8 months of immersion. The theory is useful in explaining the interaction forces between the surface and microalgae cells at any moment in time, but it should be complemented with models to predict the conditioning film formation and the contribution of the PBR’s fluid dynamics over time.

Published
2023
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32. Adsorption Analysis of Exopolymeric Substances as a Tool for the Materials Selection of Photobioreactors Manufacture

Author

Ministerio de Ciencia e Innovación (España), European Commission, García-Abad, L., Soriano J., Yolanda, Cerón-García, M. d. C., Muñoz-Bonilla, Alexandra, Fernández-García, Marta, García-Camacho, Francisco, Molina-Grima, Emilio, Ministerio de Ciencia e Innovación (España), European Commission, García-Abad, L., Soriano J., Yolanda, Cerón-García, M. d. C., Muñoz-Bonilla, Alexandra, Fernández-García, Marta, García-Camacho, Francisco, and Molina-Grima, Emilio

Abstract

An improved method that allows the robust characterization of surfaces is necessary to accurately predict the biofouling formation on construction materials of photobioreactors (PBR). Exopolymeric substances (EPS), such as proteins and polysaccharides, have been demonstrated to present a similar behavior to cells in terms of surface adhesion. In this work, these EPS were used to optimize parameters, such as EPS concentration or adsorption time, to evaluate accurately the adsorption capacity of surfaces and, with it, predict the biofouling formation in contact with microalgae cultures. Once the method was optimized, the characterization of seven commercial polymeric surfaces was submitted to different abrasive particles sizes, which modified the roughness of the samples, as well as protein and polysaccharide lawns, which were prepared and carried out in order to evaluate the characteristics of these substances. The characterization consisted of the determination of surface free energy, water adhesion tension, and critical tension determined from the measurement of the contact angle, roughness, surface zeta potential, and the EPS adhesion capacity of each material. This will be useful to understand the behavior of the surface in the function of its characteristics and the interaction with the solutions of EPS, concluding that the hydrophobic and smooth surfaces present good anti-biofouling characteristics.

Published
2022

33. Influence of abiotic conditions on the biofouling formation of flagellated microalgae culture

Author

Ministerio de Ciencia e Innovación (España), European Commission, García-Abad, L., López-Rosales, L., Cerón-García, M. d. C., Fernández-García, Marta, García-Camacho, Francisco, Molina-Grima, Emilio, Ministerio de Ciencia e Innovación (España), European Commission, García-Abad, L., López-Rosales, L., Cerón-García, M. d. C., Fernández-García, Marta, García-Camacho, Francisco, and Molina-Grima, Emilio

Abstract

This work analyses the adhesion of flagellated microalgae to seven surfaces that have different water adhesion tension characteristics. Chlamydomonas reinhardtii and Isochrysis galbana, were cultivated in batch and fed-batch mode at four nitrogen/phosphorus (N/P) ratios (from 1.29 to 70) and subjected to four irradiance levels (50, 100, 200 and 400 µE·s·m) at 23 °C. Cell adhesion was greater in C. reinhardtii and a higher biomass concentration was obtained for this strain, reaching 2 g·L compared to 1 g·L for I. galbana. The adhesion of cells and exopolymeric substances was measured upon the batch and the first fed-batch reaching the stationary growth phase, observing a direct correlation between them and inversely to biomass generation in the cultures. The protein adhesion data for the different materials are comparable to those for cell adhesion coinciding with minimums of Baier's theory and Vogler. It is observed displacements in the curves as a function of the irradiance level.

Published
2022

35. Biostimulants and biofertilizers after pilot scale high pressure homogenization of Scenedesmus sp. grown in pig manure

Author

Navarro-López, Elvira, Cerón-García, María del Carmen, López-Rodríguez, Mercedes, Acién-Fernández, Francisco Gabriel, and Molina-Grima, Emilio

Abstract

Microalgae are becoming an important source of high-value products such as biostimulants, biopesticides, and other low-value products like biofertilizers or aquafeed (fatty acids and carotenoids) among others. However, extracting the biomolecules contained in the microalgae cells is difficult due to the structure and composition of the microalgal cell wall. To overcome this drawback, mechanical cell disruption methods such as high-pressure homogenization (HPH), can be applied to facilitate extracting the compounds of interest. This work focuses on optimizing the extraction of two major groups of products from microalgae biomass - biostimulants and biofertilizers. The aim of this research is to study the effect of the HPH pre-treatment on the production of these different bioproducts starting with Scenedesmus sp. biomass grown in pig sludge as the raw material. For each product the pre-treatment of the wet biomass by HPH must to be optimized to select the optimal conditions for the pressure and the number of passes. A soft treatment of the wet biomass at 200 bar is enough to observe a 10% increase in the germination index (GI) of watercress seeds, while greater treatment intensities reduce the GI with respect to the untreated biomass, possibly because applying greater treatment intensities increases the concentration of the molecules responsible for the bioactivity thus causing a toxic effect on the seeds. In the case of biofertilizers, better results have been obtained at 600 bar, achieving a hydrolysis level of 72.9 %. Finally, the determination of the concentrations of phenolic compounds and salicylic acid, related with enhanced biostimulant activity, was carried out using spectrophotometric methods and High-Performance Liquid Chromatography- diode array (HPLC), respectively.

Published
2022

42. Vortex flow reactor assessment for the purification of monoclonal antibodies from unclarified broths

Author

Redondo Miranda Rosa M, Mazzuca Sobczuk Tania, Molina Grima Emilio, and Ibáñez González María J

Subjects
Hybridomas, Chromatography, Plug flow, Chemistry, Elution, Organic Chemistry, Flow (psychology), Antibodies, Monoclonal, Laminar flow, General Medicine, Péclet number, Biochemistry, Analytical Chemistry, Vortex, Tecnología química, Mice, symbols.namesake, Adsorption, Axial compressor, Immunoglobulin G, Fermentation, symbols, Animals
Abstract

The vortex flow reactor (VFR) can be used in many chemical engineering applications. This paper assesses its novel use in the purification of monoclonal antibodies from cell broth. To this end, the IgG2a antibody was purified from the unclarified fermentation broth of transgenic mouse 55/6 hybridoma cells. Visual experiments showed that the VFR worked in the laminar vortices flow regime and the vortices displaced slightly faster than the axial flow. The VFR has the advantage of creating two sorts of flows: axial flow to produce the expanded bed and an extra vortex flow to avoid channeling and stabilize the expanded bed, the hydrodynamic behavior of which is plug flow with an experimental Peclet number higher than 20. The pH was adjusted in the untreated fermentation broth, which was directly introduced into the reactor thus reducing the number of stages. The IgG2a purification was carried out in a single device via two steps: antibody adsorption in the expanded bed and antibody elution in the settled bed using Streamline rProtein A. A thirty-fold increase in the high-purity antibody concentration was achieved at the top of the pH5 elution peak with a total recovery of 93.1% (w/w) between elution peaks pH 5 and 3.

Published
2021

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