Francisco Javier Deive Herva

Publications (28) View all

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  Available from: Francisco Javier Deive Herva

  Article: Approaching chlorpyrifos bioelimination at bench scale bioreactor.

  F Moscoso, I Teijiz, F J Deive, M A Sanromán
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  ABSTRACT: Chlorpyrifos (CP) is one of the most commonly applied insecticides for control of pests and insects. The inappropriate use of this kind of chemicals has caused heavy contamination of many terrestrial and aquatic ecosystems thus representing a great environmental and health risk. The main purpose of this work is to investigate novel microbial agents (Pseudomonas stutzeri and the previously obtained consortium LB2) with the ability to degrade CP from polluted effluents. This goal was achieved by operating at different lab scales (flask and bioreactor) and operation modes (batch and fed-batch). Very low degradation and biomass levels were detected in cultures performed with the consortium LB2. In contrast, near complete CP degradation was reached by P. stutzeri at the optimal conditions in less than 1 month, showing a depletion rate of 0.054 h(-1). The scale-up at bench scale stirred tank bioreactor allowed improving the specific degradation rate in ten folds and total CP degradation was obtained after 2 days. Moreover, biomass and biodegradation profiles were modelled to reach a better characterization of the bioremediation process.
  Bioprocess and Biosystems Engineering 01/2013; · 1.81 Impact Factor
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  Available from: Ana Rodriguez

  Article: On the phase behaviour of polyethoxylated sorbitan (Tween) surfactants in the presence of potassium inorganic salts

  María S Álvarez, Fátima Moscoso, Francisco J Deive, M Ángeles Sanromán, Ana Rodríguez
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  ABSTRACT: a b s t r a c t The salting out potential of potassium-based inorganic salts was assessed in aqueous solutions of two non-ionic surfactants from the Tween family. New solubility data of the systems {surfactant (Tween 20/Tween 80) + inorganic salt (K 3 PO 4 /K 2 CO 3 /K 2 HPO 4 /K 2 S 2 O 3 /K 2 SO 3) + H 2 O} were experimentally ascer-tained at T = 298.15 K and these data were correlated by means of several three and four parameters empirical equations. Tie-line data were determined for the aqueous ternary systems and Ohtmer-Tobias and Bancroft equations have been proposed to correlate these data. The phase segregation effect of the proposed salts was investigated and compared with the sequence indicated by the Hofmeister series and the molar Gibbs energy of hydration (D hyd G) data.
  Chem-Bio Informatics Journal 08/2012;
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  Available from: Ana Rodriguez

  Article: On the phase behaviour of polyethoxylated sorbitan (Tween) surfactants in the presence of potassium inorganic salts

  María S Álvarez, Fátima Moscoso, Francisco J Deive, M Ángeles Sanromán, Ana Rodríguez
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  ABSTRACT: a b s t r a c t The salting out potential of potassium-based inorganic salts was assessed in aqueous solutions of two non-ionic surfactants from the Tween family. New solubility data of the systems {surfactant (Tween 20/Tween 80) + inorganic salt (K 3 PO 4 /K 2 CO 3 /K 2 HPO 4 /K 2 S 2 O 3 /K 2 SO 3) + H 2 O} were experimentally ascer-tained at T = 298.15 K and these data were correlated by means of several three and four parameters empirical equations. Tie-line data were determined for the aqueous ternary systems and Ohtmer-Tobias and Bancroft equations have been proposed to correlate these data. The phase segregation effect of the proposed salts was investigated and compared with the sequence indicated by the Hofmeister series and the molar Gibbs energy of hydration (D hyd G) data.
  The Journal of Chemical Thermodynamics 08/2012; · 2.42 Impact Factor
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  Available from: Francisco Javier Deive Herva

  Article: North Western Spain hot springs are a source of lipolytic enzyme-producing thermophilic microorganisms.

  Francisco J Deive, María S Alvarez, M Angeles Sanromán, Maria A Longo
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  ABSTRACT: Several hot springs in Galicia (North Western Spain) have been investigated as potential sources of lipolytic enzyme-producing thermophilic microorganisms. After isolating 12 esterase producing strains, 9 of them were assured to be true lipase producers, and consequently grown in submerged cultures, obtaining high extracellular activities by two of them. Furthermore, a preliminary partial characterization of the crude lipase, obtained by ultrafiltration of the cell-free culture supernatant, was carried out at several pH and temperature values. It is outstanding that several enzymes turned out to be multiextremozymes, since they had their optimum temperature and pH at typical values from thermoalkalophiles. The thermal stability in aqueous solution of the crude enzymes was also assayed, and the influence of some potential enzyme stabilizing compounds was tested. Finally, the viability of the selected microorganisms has been demonstrated at bioreactor scale.
  Bioprocess and Biosystems Engineering 07/2012; · 1.81 Impact Factor
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  Available from: Francisco Javier Deive Herva

  Article: Thermostable lipolytic enzymes production in batch and continuous cultures of Thermus thermophilus HB27

  Alberto Domínguez, Francisco J. Deive, Lorenzo Pastrana, Maria L. Rúa, Maria A. Longo, M. Angeles Sanroman
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  ABSTRACT: Several studies in laboratory-scale bioreactors are undertaken in order to verify the beneficial effect of thermal spring water in the culture medium of Thermus thermophilus HB27. Two bioreactor configurations, stirred tank and airlift, are investigated to determine the most suitable one to develop a continuous process. Water mineral composition affects the lipolytic enzyme secretion and growth of T. thermophilus HB27 in both bioreactor configurations. Furthermore, the lipolytic activity is strongly enhanced when stirred tank bioreactor is used. Moreover, operation in a stirred tank at an agitation rate of 650 rpm leads to the highest total lipolytic activity (intra- and extracellular enzyme) around 280U/L after 32h. Continuous cultures operating in the optimised conditions determined in batch cultures are carried out. It is noticeable that the stirred tank bioreactor was able to operate in a continuous flow mode without operational problems. In addition, the lipolytic activity obtained is about 2-fold higher than that attained in batch cultures.
  Bioprocess and Biosystems Engineering 04/2012; 33(3):347-354. · 1.81 Impact Factor