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Start Over Author "BENCIVENGA U." Journal biotechnology and bioengineering
5 results on '"BENCIVENGA U."'

1. A novel packed-bed bioreactor operating under isothermal and non-isothermal conditions

Author

DE MAIO, A., EL MASRY, M., DI MARTINO, S., Rossi, S., Bencivenga, U., Grano, V., Diano, N., Portaccio, M., Canciglia, Paolo, Mita, M. G., A., DE MAIO, M., EL MASRY, S., DI MARTINO, S., Rossi, U., Bencivenga, V., Grano, Diano, Nadia, P., Canciglia, and D. G., Mita

Subjects
ARTHROBACTER SIMPLEX, Immobilized enzyme, non isothermal, beta galactosidase, STEROID CONVERSION, Bioengineering, Methacrylate, Applied Microbiology and Biotechnology, Isothermal process, POROUS MEMBRANES, chemistry.chemical_compound, Bioreactor, PART 2, NYLON GRAFTED MEMBRANES, ALPHA AMYLASE, Packed bed, Chromatography, Chemistry, Polyacrylic acid, Temperature, packed bed bioreactor, isothermal, bioreactors, immobilized enzymes, PENICILLIN G ACYLASE, ASPERGILLUS ORYZAE, IMMOBILIZATION, technology, industry, and agriculture, Membranes, Artificial, Equipment Design, Hydrogen-Ion Concentration, Enzymes, Immobilized, beta-Galactosidase, Kinetics, Membrane, Thermodynamics, Glutaraldehyde, Biotechnology
Abstract

A novel packed-bed bioreactor, operating under isothermal and non-isothermal conditions, has been constructed. The core of the apparatus consisted in a polypropylene ring filled with beta-galactosidase immobilized on beads of polyacrylic acid, grafted with dimethylaminoethyl methacrylate. Phenylendiamine and glutaraldehyde were used as spacer and coupling agent, respectively. Two lateral nylon membranes held the enzyme beads into the ring and allowed the occurrence of the process of thermodialysis when the bioreactor was operating under non-isothermal conditions. Comparison of the enzyme activity under isothermal and non-isothermal conditions has shown that in the presence of temperature gradients the rate of lactose hydrolysis was increased, with a reduction of the apparent Km value. Under non-isothermal conditions the percentage increases of enzyme activity were found to decrease with the increase of the substrate concentration. The results have been explained within the frame of reference of the process of thermodialysis.

Published
2004
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2. Advantages in using immobilized thermophilic beta-glycosidase in nonisothermal bioreactors

Author

FEBBRAIO F, STELLATO S, ROSSI S, BENCIVENGA U, NUCCI R, ROSSI M, GAETA FS, MITA DG, PORTACCIO, Marianna Bianca Emanuela, Febbraio, F, Portaccio, Marianna Bianca Emanuela, Stellato, S, Rossi, S, Bencivenga, U, Nucci, R, Rossi, M, Gaeta, F, and Mita, Dg

Subjects
Kinetics, Bioreactors, Glycoside Hydrolases, Escherichia coli, Thermodynamics, Membranes, Artificial, Equipment Design, Enzymes, Immobilized, Polytetrafluoroethylene, Catalysis, Recombinant Proteins
Abstract

Catalytic membranes, obtained by immobilizing thermophilic beta-glycosidase onto nylon supports, were used in a nonisothermal bioreactor to study the effect of temperature gradients on the rate of enzyme reaction. Two experimental approaches were carried out to explain the molecular mechanisms by which the temperature gradients affect enzyme activity. The results showed that the thermophilic enzyme behaved as the mesophilic beta-galactosidase, exhibiting an activity increase which was linearly proportional to the transmembrane temperature difference. The efficiency of the system proposed was determined by calculating two constants, alpha and beta, which represent respectively the percentage increase of enzyme activity when a temperature difference of 1 degrees C or a temperature gradient of 1 degrees C cm-1 were applied across the catalytic membrane. The increase of enzyme activity in nonisothermal bioreactors entailed a proportional reduction of production times. The advantages in using thermophilic enzymes immobilized in nonisothermal bioreactors are also discussed.

Published
1999

3. Advantages of using non-isothermal bioreactors for the enzymatic synthesis of antibiotics: the penicillin G acylase as enzyme model

Author

Travascio P., Zito E., De Maio A., Schrokn C. G. P. H., Durante D., De Luca P., Bencivenga U., and Mita D. G..

Subjects
Cephalexin, Temperature, Membranes, Artificial, Equipment Design, Hydrogen-Ion Concentration, Enzymes, Immobilized, Sensitivity and Specificity, Catalysis, Anti-Bacterial Agents, Cephalosporins, Nylons, Bioreactors, Coated Materials, Biocompatible, Models, Chemical, Propylene Glycols, Escherichia coli, Methacrylates, Penicillin Amidase, Hydrophobic and Hydrophilic Interactions
Abstract

A new hydrophobic and catalytic membrane was prepared by immobilizing Penicillin G acylase (PGA, EC.3.5.1.11) from E. coli on a nylon membrane, chemically grafted with butylmethacrylate (BMA). Hexamethyldiamine (HMDA) and glutaraldehyde (Glu) were used as a spacer and coupling agent, respectively. PGA was used for the enzymatic synthesis of cephalexin, using D(-)-phenylglycine methyl ester (PGME) and 7-amino-3-deacetoxycephalosporanic acid (7-ADCA) as substrates. Cephalexin production was studied in a bioreactor operating under non-isothermal conditions, and was found to linearly increase with the applied temperature gradient. A temperature difference of about 3 °C across the catalytic membrane resulted into a cephalexin synthesis increase of 100 % with a 50 % reduction of the production times. The efficiency of the system was also determined at various concentrations of the two substrates, by calculating the a* coefficients, which represent the percentage increase of enzyme activity when a unit temperature difference is applied across the catalytic membrane. An equation relating the percentage reduction of the production times to the percentage activity increases was also determined. The membrane was also physically characterized, by estimating its hydrophobicity through the values of the hydraulic and thermoosmotic permeability coefficients. The advantage of using non-isothermal bioreactors in biotechnological processes, including pharmaceutical applications, is also discussed

Published
2002

5. Advantages in using immobilized thermophilic beta-glycosidase in nonisothermal bioreactors.

Author

Febbraio F, Portaccio M, Stellato S, Rossi S, Bencivenga U, Nucci R, Rossi M, Gaeta FS, and Mita DG

Subjects
Bioreactors, Catalysis, Equipment Design, Escherichia coli enzymology, Kinetics, Membranes, Artificial, Polytetrafluoroethylene, Recombinant Proteins metabolism, Thermodynamics, Enzymes, Immobilized metabolism, Glycoside Hydrolases metabolism
Abstract

Catalytic membranes, obtained by immobilizing thermophilic beta-glycosidase onto nylon supports, were used in a nonisothermal bioreactor to study the effect of temperature gradients on the rate of enzyme reaction. Two experimental approaches were carried out to explain the molecular mechanisms by which the temperature gradients affect enzyme activity. The results showed that the thermophilic enzyme behaved as the mesophilic beta-galactosidase, exhibiting an activity increase which was linearly proportional to the transmembrane temperature difference. The efficiency of the system proposed was determined by calculating two constants, alpha and beta, which represent respectively the percentage increase of enzyme activity when a temperature difference of 1 degrees C or a temperature gradient of 1 degrees C cm-1 were applied across the catalytic membrane. The increase of enzyme activity in nonisothermal bioreactors entailed a proportional reduction of production times. The advantages in using thermophilic enzymes immobilized in nonisothermal bioreactors are also discussed., (Copyright 1998 John Wiley & Sons, Inc.)

Published
1998

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