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Production of biomas and β‐ D ‐galactosidase by Candida pseudotropicalis grown in continuous culture on whey
Author(s) -
Gomez Amand,
Castillo Francisco J.
Publication year - 1983
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260250514
Subject(s) - lactose , yeast , enzyme , tryptophan , yeast extract , food science , chemistry , biochemistry , growth medium , enzyme assay , biology , chromatography , fermentation , amino acid , bacteria , genetics
The production of biomass and β‐ D ‐galactosidase by the lactose‐utilizing yeast Candida pseudotropicalis NCYC 744 in whey medium was studied. Apparent optimization of growth conditions and medium was done in continuous culture. Optimaql pH and temperature were 2.6 and 36–38°C, respectively, Limitations in Cu, Zn, and possbily Mn were detected in deproteinized whey medium. Additions of tryptophan estimulated growth of the yeast. Under optimal conditions in medium supplemented with excess tryptophan, Cu, Zn, and Mn the maximum values obtained: yeast concentration, 4.6 g/L; yeast productivity, 1.4 g/L h (at D = 0.35 h −1 ); enzyme volumetric productivity, 2100 U/L h (at D = 0.25 h −1 ); maintenance coefficient, 5–10 mg lactose/g cell h; saturation constant ( K s ) for lactose, 4.76m M ; maximum specific growth rate, (μ max ), 0.47 h −1 . No significant increase in specific enzyme activity (U/mg cell) was observed after medium optimiztion evidencing the importance of regulatory controls in enzyme synthesis.