Microbial sensor for new-generation cephalosporins based in a protein- engineered ß-lactamase


Por: García J.L., Nuñez C.J., González E.G., Osuna J., Soberón X., Galindo E.

Publicada: 1 ene 1998
Resumen:
A protein-engineered ?-lactamase, constructed by site-directed mutagenesis in Escherichia coli (E104M/G238S), and having broadened specificity, was able to degrade cephalosporins of first, second, and third generations. Manipulations of culture conditions allowed an increase in ?- lactamase specific activity by up to twofold. The resultant bacteria were used to construct an immersable whole-cell biosensor for the detection of new-generation cephalosporins. Cells were immobilized on agar membranes, which in turn were attached to the surface of a flat pH electrode, thus constituting a biosensor based on the detection of pH changes. The sensor was able to detect second- and third-generation cephalosporins: cefamandole (0.4- 4 mM), cefotaxime (0.4-3.5 mM), and cefoperazone (0.3-1.85 mM). Response times were between 3.5 and 11 min, depending on the kind of cephalosporin tested. The biosensor was stable for at least 7 d, time during which up to 100 tests were performed.

Filiaciones:
García J.L.:
 Department of Bioengineering, Institute of Biotechnology, National University of Mexico, Apdo. Postal 510-3, Cuernavaca, Morelos, 62250, Mexico

Nuñez C.J.:
 Department of Bioengineering, Institute of Biotechnology, National University of Mexico, Apdo. Postal 510-3, Cuernavaca, Morelos, 62250, Mexico

González E.G.:
 Department of Bioengineering, Institute of Biotechnology, National University of Mexico, Apdo. Postal 510-3, Cuernavaca, Morelos, 62250, Mexico

Osuna J.:
 Dept. Molec. Recog. and Biostructure, Institute of Biotechnology, National University of Mexico, Apdo. Postal 510-3, Cuernavaca, Morelos, 62250, Mexico

Soberón X.:
 Dept. Molec. Recog. and Biostructure, Institute of Biotechnology, National University of Mexico, Apdo. Postal 510-3, Cuernavaca, Morelos, 62250, Mexico

Galindo E.:
 Department of Bioengineering, Institute of Biotechnology, National University of Mexico, Apdo. Postal 510-3, Cuernavaca, Morelos, 62250, Mexico
ISSN: 02732289
Editorial
HUMANA PRESS INC, 999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA, Estados Unidos America
Tipo de documento: Article
Volumen: 73 Número: 2-3
Páginas: 243-256
WOS Id: 000076190400013
ID de PubMed: 9779580