Original scientific paper
Use of Response Surface Methodology to Predict Optimal Conditions of Kluyveromyces lactis Permeabilization by a Physical Method
J. Teles de Faria
; Department of Food Technology, Federal University of Viçosa, Av. P. H. Rolfs s/n, 36571-000 Viçosa, Minas Gerais, Brazil
M. Lopes Moraes
; Department of Pharmacy, Federal University of Jequitinhonha and Mucuri, Rua da Glória, 187, 39100-000 Diamantina, Minas Gerais, Brazil
A. Del Borghi
; Department of Chemical and Process Engineering, University of Genoa, via Opera Pia 15, 16145 Genoa, Italy
A. Converti
; Department of Chemical and Process Engineering, University of Genoa, via Opera Pia 15, 16145 Genoa, Italy
F. M. Lopes Passos
; Department of Microbiology, Federal University of Viçosa, Av. P. H. Rolfs s/n, 36571-000 Viçosa, Minas Gerais, Brazil
L. A. Minim
; Department of Food Technology, Federal University of Viçosa, Av. P. H. Rolfs s/n, 36571-000 Viçosa, Minas Gerais, Brazil
A. P. de F. C. Vanzela
; Department of Food Technology, Federal University of Viçosa, Av. P. H. Rolfs s/n, 36571-000 Viçosa, Minas Gerais, Brazil
F. Coelho Sampaio
; Department of Pharmacy, Federal University of Jequitinhonha and Mucuri, Rua da Glória, 187, 39100-000 Diamantina, Minas Gerais, Brazil
Abstract
Kluyveromyces lactis is an important commercial source of β-galactosidase, an enzyme of major concern for dairy industry. Among the methods for β-galactosidase recovery, cell permeabilization is the best alternative, but it is influenced by a number of operating conditions that need to be optimized. Aim of this study was to determine the best experimental conditions for yeast cells permeabilization by physical disruption with glass beads. Influence of glass beads and dry biomass amounts and process time was investigated varying these independent variables according to a central composite rotatable experimental design. A third order polynomial equation was fitted to the experimental data of permeabilized cells β-galactosidase activity, and the Response Surface Methodology employed for optimization. Optimum permeabilization conditions (0.90 g glass beads, 2.00 g dry biomass and 8.0 min of treatment) ensured a maximum β-galactosidase
activity (6,434 mmol L–1 oNP min–1 g–1) in reasonable agreement with the yield reproduced under the same conditions (5,585.40 mmol L–1 oNP min–1 g–1).
Keywords
Cheese whey; Kluyveromyces lactis; yeast; β-galactosidase; glass beads
Hrčak ID:
83958
URI
Publication date:
4.7.2012.
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