Microbial Biotechnology

Process 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 April 10, 2008 / Accepted August 4, 2008
DOI: 10.2225/vol11-issue4-fulltext-12

Optimization of β-galactosidase production using Kluyveromyces lactis NRRL Y-8279 by response surface methodology

Seval Dagbagli
Department of Food Engineering
Faculty of Engineering
Ege University
35100 Bornova İzmir, Turkey
Tel: 90 232 3884000. Ext. 3003
Fax: 90 232 3427592
E-mail: seval.dagbagli@ege.edu.tr

Yekta Goksungur*
Department of Food Engineering
Faculty of Engineering
Ege University
35100 Bornova İzmir, Turkey
Tel: 90 537 405 29 24
Fax: 90 232 3427592
E-mail: yekta.goksungur@ege.edu.tr

*Corresponding author

Financial support: This research was supported by the State Planning Organization (Turkey) through Project no: DPT.2005K120570 and Scientific and Technical Research Council of Turkey (TÜBİTAK) through Project no: TOVAG 104 O 270.

Keywords: β-galactosidase, Kluyveromyces lactis, response surface methodology, shake flask culture, synthetic medium.


DNS: dinitrosalicylic acid
ONP: o-nitrophenol
ONPG: ο-nitrophenol-β-D-galactopyranoside
P: probability
RSM: response surface methodology
SDS: sodium dodecyl sulfate

Abstract   Full Text

This paper investigates the production and optimization of β-galactosidase enzyme using synthetic medium by Kluyveromyces lactis NRRL Y-8279 in shake flask cultures. Among the different cell disintegration methods used, the highest specific activity was obtained when the cells were permeabilized using isoamyl alcohol. Response surface methodology was used to investigate the effects of four fermentation parameters (agitation speed, pH, initial substrate concentration and incubation time) on β-galactosidase enzyme production. Results of the statistical analysis showed that the fit of the model was good in all cases. Maximum specific enzyme activity of 4218.4 U g-1 was obtained at the optimum levels of process variables (pH 7.35, agitation speed 179.2 rpm, initial sugar concentration 24.9 g l-1 and incubation time 50.9 hrs). The response surface methodology was found to be useful in optimizing and determining the interactions among process variables in β-galactosidase enzyme production.

Supported by UNESCO / MIRCEN network