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Abstract:
The biochemical properties of all four β-galactosidases from Aspergillus niger strain F0215 were investigated. The genes encoded β-galactosidases were cloned and expressed in Pichia pastoris GS115. The recombinants GS115 (PIC-bgl A), GS115 (p PIC-bgl B), GS115 (p PIC-bgl C) and GS115 (p PIC-bgl E) were subsequently constructed and the recombinant β-galactosidases BglA, BglB, BglC and BglE were prepared by using shaking flask fermentation and methanol induction followed by comprehensive investigation of their biochemical properties. The temperature optimum of BglA, BglB, BglC or BglE was 60, 50, 60 and 50 , respectively, the p H optima were of 4.0, 4.5, 3.5 and 4.5, respectively. Their activities were enhanced by Mg2+, Ca2+, Na+or Mn2+but significantly inhibited by Cu2+, Fe2+, Ni2+, Zn2, Li+or EDTA. The Km value of BglA, BglB, BglC or BglE towards ONPG was determined to be 0.43, 0.22, 0.37 mmol/L and 0.46 mmol/L. BglA, BglB, BglC and BglE performed a specificity towards lactose as sole substrate with the activities of hydrolysis and transglycosylation. All identified four β-galactosidases possessed a typical molecular structure of fungalβ-galactosidases. β-Galactosidase BglD was not existed in the test strain although it was predicted in the reference genome sequence. © 2017, Editorial Office of Journal of CIFST. All right reserved.
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Journal of Chinese Institute of Food Science and Technology
ISSN: 1009-7848
Year: 2017
Issue: 11
Volume: 17
Page: 198-207
Cited Count:
WoS CC Cited Count: 0
SCOPUS Cited Count: 1
ESI Highly Cited Papers on the List: 0 Unfold All
WanFang Cited Count:
Chinese Cited Count:
30 Days PV: 2
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