Process Biotechnology

Microbial Biotechnology

Electronic Journal of Biotechnology ISSN: 0717-3458 Vol. 11 No. 4, Issue of October 15, 2008
© 2008 by Pontificia Universidad Católica de Valparaíso -- Chile Received March 25, 2008 / Accepted June 16, 2008
DOI: 10.2225/vol11-issue4-fulltext-6

Kinetic study on inducibility of polygalacturonases from Aspergillus flavipes FP-500

Aurora Martínez-Trujillo
Laboratorio de Catálisis Enzimática
Tecnológico de Estudios Superiores de Ecatepec
Av. Tecnológico s/n esq. Av. Carlos Hank González
Ecatepec, Estado de México, CP 55210, México
Tel: 01 55 00 23 00. Anexo 2227

Juan S. Aranda
Departmento de Bioingeniería
Unidad Profesional Interdisciplinaria de Biotecnología
Instituto Politécnico Nacional
Av. Acueducto s/n, Col. La Laguna Ticoman
D.F.CP 07340, México
Tel: 01 57 29 60 00. Anexo 56338

Guillermo Aguilar-Osorio*
Departamento de Alimentos y Biotecnología
Facultad de Química
Universidad Nacional Autónoma de México
Ciudad Universitaria, Conj. E, Química
CP 04510, D.F., México
Tel: 52 55 56 22 53 05.

*Corresponding author

Financial support: This work was financially supported by the National Council for Science and Technology (Mexico), the Technologic Institute for Higher Studies of Ecatepec (México), the Research Office of the National Polytechnique Institute (Mexico), and the National University of Mexico, DGAPA projects IN207603 and IN209008.

Keywords: constitutive enzymes, inducible enzymes, initial pH, kinetic modeling, pectinases.

Abstract   Full Text

The aim of this work was to describe growth dynamics, substrate depletion and polygalacturonases production by Aspergillus flavipes FP-500 in batch cultures by means of unstructured models. The microorganism was cultivated on several mono- di- and poly- saccharides, and then the culture development modeled with Monod and Leudeking-Piret equations. The kinetic parameters related to the models (µmax, γx/s, α and β) were obtained by minimizing the quadratic residuals function with a simplex algorithm. An accurate description of experimental data was attained with the proposed models. Besides, modeling provided significant kinetic information on microbial degradation of complex substrates, such as the correlation between specific growth rate µmax and production yield α, suggesting that A. flavipes FP-500 polygalacturonases are actually constitutive, but also that there is a certain degree of induciblility in these enzymatic activities.

Supported by UNESCO / MIRCEN network