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6. Membrane cell retention systems for continuous production of l-carnitine using Proteus sp.

Author

Cánovas, M., Maiquez, J., De Diego, T., Buendıa, B., Espinosa, G., and Iborra, J.L.

Subjects
*MEMBRANE reactors, *BIOTRANSFORMATION (Metabolism)
Abstract

Membrane reactors with a Proteus sp. strain as the biocatalyst were used to attain continuous l-carnitine production from crotonobetaine. Hollow fiber cartridges with fibers of polysulfone provided adequate filtration rates and were reusable after long-term operation (consecutive runs of 140 h followed). Running under optimum medium composition, these systems enabled high cell densities (35–45 g dry weight/l) to be reached after 35–40 h at dilution rates ranging from 0.1 to 1.5 h−1, while cross-flow filtration units with flat-sheet membranes made of polyvinylidene difluoride (PVDF) showed lower cell concentrations (up to 25 g dry weight/l) and levels of l-carnitine production. The composition of the hollow fiber membranes probably improved filtration flow rates and definitely speed up the cleaning-up procedure because cake layers did not adhere tightly to the membranes. Furthermore, resting cell-cycles were maintained in continuous operation for 2–3 days with crotonobetaine and phosphate buffer as the only medium components, followed by cycles of cell re-activation, meaning that the system was stable for long periods of time (140–200 h). During resting cell-cycles, high cell decay rates were observed due to nutrient shortages. The hollow fiber system was able to produce high levels of l-carnitine during the growing/resting cycles with 35–50% conversion and productivities as high as 40.5 g/(l h). The optimum dilution rate was 1.0 h−1 as mass-transfer problems appeared at higher dilution rates because of high cell densities. The process described is presented as a way of recycling d-carnitine from the chemical industry, since, when dehydrated, this compound renders crotonobetaine. [Copyright &y& Elsevier]

Published
2003
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8. Modeling of the biotransformation of crotonobetaine into <SC>L</SC>-(−)-carnitine by <TOGGLE>Escherichia coli</TOGGLE> strains

Author

Canovas, M., Maiquez, J. R., Obón, J. M., and Iborra, J. L.

Abstract

A simple unstructured model, which includes carbon source as the limiting and essential substrate and oxygen as an enhancing substrate for cell growth, has been implemented to depict cell population evolution of two Escherichia coli strains and the expression of their trimethylammonium metabolism in batch and continuous reactors. Although the model is applied to represent the trans-crotonobetaine to L-(−)-carnitine biotransformation, it is also useful for understanding the complete metabolic flow of trimethylammonium compounds in E. coli. Cell growth and biotransformation were studied in both anaerobic and aerobic conditions. For this reason we derived equations to modify the specific growth rate, μ, and the cell yield on the carbon source (glycerol), Yxg, as oxygen increased the rate of growth. Inhibition functions representing an excess of the glycerol and oxygen were included to depict cell evolution during extreme conditions. As a result, the model fitted experimental data for various growth conditions, including different carbon source concentrations, initial oxygen levels, and the existence of a certain degree of cell death. Moreover, the production of enzymes involved within the E. coli trimethylammonium metabolism and related to trans-crotonobetaine biotransformation was also modeled as a function of both the cell and oxygen concentrations within the system. The model describes all the activities of the different enzymes within the transformed and wild strains, able to produce L-(−)-carnitine from trans-crotonobetaine under both anaerobic and aerobic conditions. Crotonobetaine reductase inhibition by either oxygen or the addition of fumarate as well as its non-reversible catalytic action was taken into consideration. The proposed model was useful for describing the whole set of variables under both growing and resting conditions. Both E. coli strains within membrane high-density reactors were well represented by the model as results matched the experimental data. © 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 764–775, 2002; DOI 10.1002/bit.10157

Published
2002
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9. High-density Escherichia coli cultures for continuous <span style="font-variant:small-caps">l</span> (−)-carnitine production

Author

Obón, J. M., Maiquez, J. R., Cánovas, M., Kleber, H.-P., and Iborra, J. L.

Abstract

Abstract: The use of a biological procedure for l-carnitine production as an alternative to chemical methods must be accompanied by an efficient and highly productive reaction system. Continuous l-carnitine production from crotonobetaine was studied in a cell-recycle reactor with Escherichia coli O44 K74 as biocatalyst. This bioreactor, running under the optimum medium composition (25 mM fumarate, 5 g/l peptone), was able to reach a high cell density (26 g dry weight/l) and therefore to obtain high productivity values (6.2 g l-carnitine l−1 h−1). This process showed its feasibility for industrial l-carnitine production. In addition, resting cells maintained in continuous operation, with crotonobetaine as the only medium component, kept their biocatalytic capacity for 4 days, but the biotransformation capacity decreased progressively when this particular method of cultivation was used.

Published
1999
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11. Staphylococcus spp. in Spain: Present situation and evolution of antimicrobial resistance (1986-2006) | Staphylococcus spp. en España: Situación actual y evolución de la resistencia a antimicrobianos (1986-2006)

Author

Cuevas, Ó, Cercenado, E., Goyanes, M. J., Vindel, A., Trincado, P., Boqueteb, T., Marín, M., Bouza, E., Sicilia, A., Reyes, A., Herruzo, J. G., Marín, P., Ruiz, I., Calbo, L., Ramírez, J. L. D. F., Arrimadas, E., Porto, A. S., Casal, M., Del Río, M. C., Plata, C., Tejero, R., La Rosa, M., Bautista, Ma F., Maroto, C., Escobar, T., Pascual, L., Saavedra, J., Cuesta, I., Carazo, I., Molina, J. H., Pinedo, A., García, Ma V., Gallardo, M., Pascual, Á, Cueto, M., Perea, E., Aznar, J., Crespo, M. D. T., Mazuelos, E. M., López, J. L. G., Ferrero, M., Chocarro, P., Navarro, C., Torres, L., Miñana, C., Revillo, Ma J., Rezusta, A., Rubio, C., Durán, E., Vázquez, F., Aranaz, C., Santos, Ma J., Fleites, A., Lantero, M., Folgueras, I. S., Hidalgo, E., Otero, L., Miguel, Ma D., Prendes, P., Galarraga, Ma C., Sierra, G., La Iglesia, P., Ordás, J. F., Barreiro, L., Pérez, J. L., Borrell, N., Oliver, A., Gómez, J. S., Hurtado, A., Batista, N., González, I. G., Sierra, A., Gómez, Ma A. M., Martín, A. M., Hernández, A., Martínez, L. M., Campo, A. B., La Fuente, C. G., Mellado, P., Crespo, Ma D., Escribano, E., Palomar, J. J., Romero, Ma D., Solís, S., Carranza, R., Medina, C. M., Seseña, G., Bisquert, J., Tena, D., Pierna, L. D., Castañar, Ma V. M., Leturia, A. Ma, Ibáñez, R., Arroyo, R. S., Pozas, I., Ojeda, E., Mejías, G., Lizondo, C., Badía, Ma D., Gimeno, C., Junquera, S., Cachón, F., Natal, Ma I. F., Fuster, C., Alonso, E. Á, Castro, Ma A. G., Sánchez, J. E. G., Rodríguez, J. Á G., Vázquez, M. F., Carbajosa, S. G., Carrero, P., Real, S. H., Campos, Á, Betrán, A., Aldea, C., Pascual, P. P., Alberte, A., Torres, A. R., Bratos, M. Á, Lorenzo, B., Brezmes, Ma F., Urrutia, L. L., Prats, G., Anta, Ma T. J., Marco, F., Coll, P., Mirelis, B., Vilamala, A., San José, C., Martín, R., Tubau, F., Salvadó, M., González, A., Fontanals, D. D., Lite, J., Corcoy, F., Angrill, R., Morta, M., Estivill, D., Urcuola, Ma L., Surroca, J. D. B., Motje, M., Nogues, A., García, M., Santamaría, J. Ma, Gómez, F., Tapiol, J., Barba, J. L., Blanco, J., Teno, P., Viñuelas, J., Villanueva, R., González, A. F., Jove, M. R., Agulla, A., Mayo, M. R., Regueiro, B., Pardo, F., Alonso, P., Coira, A., Esteban, G., Pérez, B. F., García, P. Á, Del Blanco, T. G., Otero, I., Torres, J., Vasallo, F. J., Sevillano, P. J., Conde, I. R., Borque, L., Olarte, I., Ugalde, E., Gutiérrez, A., Perea, A. G., Otero, J. R., Chaves, F., Gadea, I., Roblas, R. F., Hervás, F., Buezas, Ma V., Santana, P. S., Picazo, J. J., Merino, P., Baquero, F., Morosini, Ma I., Pazos, C., Baquero, M., Enríquez, A. Ma, Dámaso, D., Romero, I. S., Brea, M. L., Alarcón, T., Cortés, R., Portús, Ma V., Urmeneta, A., Beltrán, M., González, R., Garcés, J. L. G., Vargas, L., Burillo, A., Aznar, E., Sánchez, A., Rico, A., Wilhelmi, I., Criado, C. G., Delgado, A., Valverde, J., Alós, J. I., Concheiro, M. S., Galán, Ma I., Sánchez, J. A. T., Ramírez, C., Guerrero, C., Segovia, M., Yagüe, G., Menasalvas, A., Artola, V. M., Beristain, X., Pina, C., Fontaneda, A., Dorronsoro, I., Irure, J. J. G., José Leiva, Hernáez, S., Trallero, E. P., Arenzana, J. Ma G., Alfaro, J. A. J., Redondo, B., Arteche, L., Iturzaeta, A., Aguinaga, A., Cisterna, R., Ibarra, K., Calvo, F., Corral, I., Elorduy, L., Rienda, I. M., Goikoetxea, Ma J. L., Michaus, L., Perales, A., Labora, A., Canut, A., Plazas, J., López, M. A., La Tabla, V. O., Zorraquino, A., Gonzalo, N., Sánchez, V., Fuentes, E., Royo, G., López, P., Moreno, R., Del Busto, A. G., Yagüe, A., Gobernado, M., Hontangas, J. L. L., Lomas, J. G., Tormo, N., Lozano, T. G., Maiquez, J., Nogueira, J. M., Canós, M., Llucián, Ma R., Lloret, A. Ma, Bosque, M., Guerrero, A., Colomina, J., Aguayo, J. Ma G., Miguel, L. A., Jiménez, Ma C. A., Ferreruela, R. Ma, Tintorer, J. L. H., Vírseda, I., Fornells, J. P., Escoms, R., and Giner, S.

12. Evolution of the antimicrobial resistance of Pseudomonas aeruginosa in Spain: Second National Study (2003)

Author

Sánchez-Romero, I., Cercenado, E., Cuevas, O., García-Escribano, N., García-Martínez, J., Bouza, E., Rodríguez-Jove, M., Álvarez, A., Agulla, J. A., Rodríguez-Mayo, M., Regueiro, B., Pardo, F., Alonso, P., Coira, A., Tinajas, A., Pulian, V., García-Campello, M., González-Blanco, T., Otero, I., Torres, J., Vasallo, F. J., Sevillano, J., Rodríguez-Conde, I., Vázquez, F., Aranaz, C., Méndez, F., Lantero, M., Hidalgo, E., Viejo, G., Miguel, M. D., Prendes, P., Rodríguez-Álvarez, J., Cimadevilla, R., Torreblanca, A., Martinez, L., Calvo, J., Colomo, L. F., Mellado, P., Cisterna, R., Ibarra, K., Calvo, F., Marzana, I., Martín-Saco, G., Alkorta, M., Barrón, J., López-Goikoetxea, M. J., Michaus, L., Pablos, M., Labora, A., Canut, A., Pérez-Trallero, E., García-Arenzana, J. M., Jiménez-Alfaro, J. A., Jauregui, A., Torroba, L., Pina, C., Fontaneda, A., Dorronsoro, I., García-Irure, J. J., Díaz-García, R., Leiva, J., Gastañares, M. J., Olarte, I., Jiménez-Anta, M. T., Marco, F., Pere Coll, Mirelis, B., Martín, R., Tubau, F., Prats, G., Larrosa, N., Salvadó, M., Fontanals, D., Mariscal, D., Lite, J., Ausina, V., Matas, L., Corcoy, F., Angrill, R., Urcula, M. L., Batlle, J., Motje, M., García-Busto, A., Moreno, R., Canós, M., Vila, B., Gobernado, M., López-Hontangas, J. L., García-Lomas, J., Navarro, D., Lloret, A., Bosque, M., Maiquez, J., Aznar, E., Nogueira, J. M., Morales, A., Llucián, M. R., García-Aguayo, J. M., Alonso, M. C., Andreu, L., González-Granda, D., Hernández, J. L., Prat, J., Escoms, R., Giner, S., Yagüe, A., Gonzalo, N., Royo, G., Cebrian, L., Altuna, A., Segovia, M., Menasalvas, A., Piqueras, J., Martínez, L., Sicilia, J. M., Ruiz, J., Vilar, V., Pérez, J. L., Borrell, N., Oliver, A., Sánchez-Gómez, J., Gutiérrez, A., García-Perea, A., Rodríguez-Otero, J. J., Chaves, F., Menéndez-Rivas, M., Hervas, F., Sánchez, P., Picazo, J. J., San Pedro, A., Baquero, F., Cantón, R., Blanco, M. A., Pazos, C., Dámaso, D., López-Brea, M., Alarcón, T., Cortés, R., Portús, V., Urmeneta, A., Beltrán, M., Gómez, P., Gómez, J. L., Tamayo, J., Wilhelmi-Cal, I., Sánchez, M., Cacho, J., Rollán, E., Pérez, T., Miñiana, C., Revillo, M. J., Rubio, C., Escartín, R., Ferrero, M., Chocarro, P., Navarro, C., Nebreda, T., Díaz, L., Brea, S., Leturia, A. M., González-Rodríguez, J. C., Barba, I., Romero, M. D., Mora, F., Bisquert, J., Pérez, M. T., Crespo, D., Escribano, E., Robles, P., Cachón, F., Fuster, C., Brezmes, M. F., López-Urrutia, L., García-Rodríguez, J. A., García-Sánchez, J. E., García-Carbajosa, S., Carrero, P., Pozas, I., Ojeda, E., Mejías, Badía, M. D., Lizondo, C., Gimeno, C., Ibáñez, R., Gómez, A., Campos, A., Merino, F., García-Castro, M. A., Álvarez, E., Rodríguez-Torres, A., Bratos, M. A., Iñiguez, R., Teno, P., Blanco, J., Garduño, E., García-Herruzo, J., Saldarreaga, A., Martín, M., Ruiz, I., Calbo, L., Francisco, J. L., Sánchez-Porto, A., Casal, M., Ibarra, A., Rosa-Fraile, M., Miranda, C., Manchado, P., Porras, J., Cuesta, I., Carazo, C., Saavedra, J. M., Pascual, L., García-Iglesias, C., Chavez, M., Perea, E., Ramírez, E., Guerrero, Y., Aznar, J., Merino, L., Martín, E., López-Barba, J., Díaz, J., Galán, M., Tur, J. A., Batista, N., Moreno, A., Sierra, A., Cuervo, M., Gallardo, R. M., Martín, A. M., Bolaños, M., Fleites, A., Santos, M. J., Esteban, G., Fernández, B., Guerrero, A., Cuenca, M., and Ramos, P.

15. Modeling of the biotransformation of crotonobetaine into L-(-)-carnitine by Escherichia coli strains.

Author

Canovas M, Maiquez JR, Obón JM, and Iborra JL

Subjects
Algorithms, Computer Simulation, Escherichia coli metabolism, Fumarates metabolism, Membranes physiology, Multienzyme Complexes antagonists & inhibitors, Oxidoreductases antagonists & inhibitors, Time Factors, Betaine analogs & derivatives, Betaine metabolism, Bioreactors, Carnitine analysis, Carnitine biosynthesis, Escherichia coli growth & development, Models, Biological
Abstract

A simple unstructured model, which includes carbon source as the limiting and essential substrate and oxygen as an enhancing substrate for cell growth, has been implemented to depict cell population evolution of two Escherichia coli strains and the expression of their trimethylammonium metabolism in batch and continuous reactors. Although the model is applied to represent the trans-crotonobetaine to L-(-)-carnitine biotransformation, it is also useful for understanding the complete metabolic flow of trimethylammonium compounds in E. coli. Cell growth and biotransformation were studied in both anaerobic and aerobic conditions. For this reason we derived equations to modify the specific growth rate, mu, and the cell yield on the carbon source (glycerol), Y(xg), as oxygen increased the rate of growth. Inhibition functions representing an excess of the glycerol and oxygen were included to depict cell evolution during extreme conditions. As a result, the model fitted experimental data for various growth conditions, including different carbon source concentrations, initial oxygen levels, and the existence of a certain degree of cell death. Moreover, the production of enzymes involved within the E. coli trimethylammonium metabolism and related to trans-crotonobetaine biotransformation was also modeled as a function of both the cell and oxygen concentrations within the system. The model describes all the activities of the different enzymes within the transformed and wild strains, able to produce L-(-)-carnitine from trans-crotonobetaine under both anaerobic and aerobic conditions. Crotonobetaine reductase inhibition by either oxygen or the addition of fumarate as well as its non-reversible catalytic action was taken into consideration. The proposed model was useful for describing the whole set of variables under both growing and resting conditions. Both E. coli strains within membrane high-density reactors were well represented by the model as results matched the experimental data., (Copyright 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 764–775, 2002; DOI 10.1002/bit.10157)

Published
2002
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16. Immunoglobulin allotypes in European populations. IV. Gm, Am and Km allotypic markers in Valencia, Spain.

Author

Schanfield MS, Baylerian R, Maiquez J, and Carbonell F

Subjects
Blood Donors, Gene Frequency, Humans, Spain, Immunoglobulin Allotypes genetics, Polymorphism, Genetic
Abstract

The distribution of Glm(f, z, a and x), G3m(b0, b1, b3, b5, c3, c5, g, s and t), A2m (1 and 2) and Km(1) allotypic determinants in a series of Spanish blood donors. The following results were obtained: Gmz,a;gAm1 = 0.199; Gmz,a;gAm2 = 0.019; Gmz,a,x;gAm1 = 0.081; Gmz,a,x;gAm2 = 0.005; Gmf;bAm1 = 0.677; Gmz,a;bAm1 = 0.019 and Km1 = 0.096. The results are similar to those reported for adjacent Basque and Portuguese populations. The origin of the Gmz,a;bAm1 haplotype is unknown.

Published
1981
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