Production of β-D-galactosidase from Kluyveromyces fragilis in batch cultures with cheese whey as substrate

Xiomara Montiel, Ingrid Carruyo, José Ferrer, Letty Marcano, Zulay Mármol, Gisela Páez


The capacity of kluyveromyces fragilis (K. marxianus) ATCC 8554 to induce the production of β-D-galactosidase during growth in deproteinized cheese whey at temperatures of 25ºC and 29ºC and at initial pH of 4.5 was studied. Enzyme activity was determined in cell-free extracts evaluating the hydrolysis of o-nitrophenyl- β-D-galactopiranoside (ONPG), as substitute for lactose. Extraction of the enzyme from fresh cells was achieved by autolysis using 2% toluene. The enzyme was released lo the medium by permeabilization and partial digestion of the cell wall, without breaking, as reveled through electron microscopy. The highest activity, 0.604 µmol ortonitrophenol /ml/5min was obtained at 29ºC initiating estationary phase. The results obtained, including the production of biomase, ulilization of substrate and cell yield indicated the possibility of developing a bioprocess with cheese whey for the production of β-D galactosidase utilizing this microorganism.

Palabras clave

β-galactosidase; K. marxianus; permeabilization; ONPG

Texto completo:


Universidad del Zulia /Venezuela/ Revista Técnica de la Facultad de Ingeniería/ /

p-ISSN: 0254-0770 / e-ISSN: 2477-9377 


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