Biology Reference
In-Depth Information
All measurements and/or experiments were conducted fi ve times. Results are pre-
sented as mean SD. Relative activities were estimated in above experiments by com-
parison to highest activity (100%).
CONCLUSION
In this study we present the purification and characterization of a new β-D-galactosidase
from
Arthrobacter
sp. 32c. From the sequence analyses it is obvious that the protein
is a member of the family 42 β-D-galactosidases. The protein weight deduced from
the 695 amino acid sequence was 75.9 kDa. Molecular sieving revealed that the active
enzyme has a molecular weight of approximately 195 ± 5 kDa and therefore it is prob-
ably a trimmer. The new characterized β-D-galactosidase is of industrial interest and
can be produced extracellularly in its economically feasible variant by the constructed
P. pastoris
strain.
The constructed
P. pastoris
strain may be used in co-fermentation of lactose from
cheese whey by a consortium of microorganisms with industrial strains of brewing
yeast
S. cerevisiae
, where the
P. pastoris
produces β-D-galactosidase in the oxygen
phase and accelerates the shift between the oxidative and reductive conditions.
KEYWORDS
•
β
-D-galactosidase
•
Arthrobacter
sp.
•
Escherichia coli
•
Half saturation coefficient
•
Pichia pastoris
•
Saccharomyces cerevisiae
strains
AUTHORS' CONTRIBUTIONS
Piotr Hildebrandt carried out the molecular genetic studies, participated in the de-
sign of the study and drafted the manuscript. Marta carried out the molecular genetic
studies, participated in drafted the manuscript. Józef Kur conceived of the study, and
participated in its design and coordination. All authors read and approved the final
manuscript.
ACKNOWLEDGMENTS
This work was supported by the Polish State Committee for Scientific Research Grant
2 P04B 002 29 to J.K.
This research work was supported by the European Social Fund, the State Bud-
get and the Pomeranian Voivodeship Budget in the framework of the Human Capital
Operational Programme, priority VIII, action 8.2, under-action 8.2.2 Regional Inno-
vative Strategies, the system project of the Pomorskie Voivodeship “Innodoktorant
Scholarships for PhD students, I edition.”
