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A new β-galactosidase extracted from the infant feces with high hydrolytic and transgalactosylation activity.
- Source :
-
Applied Microbiology & Biotechnology . Oct2019, Vol. 103 Issue 20, p8439-8448. 10p. - Publication Year :
- 2019
-
Abstract
- A β-galactosidase (β-GalINF) was directly isolated from feces of an 8-month-old infant. Mass spectrum analysis showed β-GalINF with coverage over 50% to the β-galactosidase from Bifidobacterium longum EK3. Accordingly, the β-galINF was amplified from the feces metagenomic DNA by degenerate primers. After overexpressed in Escherichia coli, the β-GalINF was purified and biochemical characterized. β-GalINF existed as homotetramer and homodimer, whose activity (optimal at 50 °C, pH 6.5) was exhilaratingly increased to 484% by artificial intestinal juice. The Km and Vmax values for oNPG and lactose were 20.95 ± 2.76 mM, 5004.50 ± 318.8 μmol min−1 mg−1 and 140.2 ± 17.7 mM, 293.1 ± 14.7 μmol min−1 mg−1, respectively. The production rate of galacto-oligosaccharides by β-GalINF from 20% lactose at 50 °C was 33.4 ± 0.67%. These results suggested the β-GalINF with high hydrolytic and transgalactosylation activity from the infant intestinal has great potential as infant lactase preparation. Moreover, this study provided a new way for exploring undetected enzymes by uncultured-dependent methods. [ABSTRACT FROM AUTHOR]
- Subjects :
- *MASS spectrometry
*DNA primers
*INFANTS
*BIFIDOBACTERIUM longum
*METAGENOMICS
Subjects
Details
- Language :
- English
- ISSN :
- 01757598
- Volume :
- 103
- Issue :
- 20
- Database :
- Academic Search Index
- Journal :
- Applied Microbiology & Biotechnology
- Publication Type :
- Academic Journal
- Accession number :
- 139215577
- Full Text :
- https://doi.org/10.1007/s00253-019-10092-x