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Purification, characterization and specificity of a new GH family 35 galactosidase from Aspergillus awamori
- Source :
- International Journal of Biological Macromolecules. 156:885-895
- Publication Year :
- 2020
- Publisher :
- Elsevier BV, 2020.
-
Abstract
- Galactosidases, ubiquitous in nature, are complex carbohydrate-active enzymes and find extensive applications in food, pharma, and biotechnology industries. The present study deals with the production of galactosidases from fungi by solid-state fermentation. Fifteen fungi were screened and Aspergillus awamori (MTCC 548), exhibited the highest α and β-galactosidase activities of 75.11±0.29 U/g and 155.34±1.26 U/g, respectively. 30 g of wheat bran substituted with 6% defatted soy flour, at 28°C, pH 5.0 for 120 h, was established as the optimum production conditions by one-factor approach. The enzyme was purified to homogeneity with an apparent mass of 118 ± 2 kDa by ammonium sulfate precipitation (50–80%), ion exchange and hydrophobic interaction chromatography. Specific activities for α and β-galactosidase were 22 and 74 U/mg, respectively. Optimum temperature and pH ranges for enzyme activities were 55–60 °C, 5.0–5.5, respectively. The thermal inactivation mid-point was 65 °C. The purified enzyme not only exhibited α and β-galactosidase activities, but also exhibited β-xylosidase and β-glucosidase activities, indicating the enzyme has broad substrate specificity. Sequence analysis by in-gel digestion and tandem mass spectrometry (MS/MS) revealed that the enzyme was a probable β-galactosidase A, belonging to glycoside hydrolase 35 family, and is being reported for the first time.
- Subjects :
- Chemical Phenomena
Oligosaccharides
Lactose
02 engineering and technology
Chemical Fractionation
Tandem mass spectrometry
Biochemistry
Substrate Specificity
03 medical and health sciences
Structural Biology
Enzyme Stability
Glycoside hydrolase
Molecular Biology
Aspergillus awamori
Ammonium sulfate precipitation
030304 developmental biology
chemistry.chemical_classification
Chromatography
0303 health sciences
Galactosidases
Hydrolysis
Spectrum Analysis
Temperature
General Medicine
Hydrogen-Ion Concentration
021001 nanoscience & nanotechnology
Enzyme Activation
Aspergillus
Enzyme
chemistry
Solid-state fermentation
Fermentation
0210 nano-technology
Subjects
Details
- ISSN :
- 01418130
- Volume :
- 156
- Database :
- OpenAIRE
- Journal :
- International Journal of Biological Macromolecules
- Accession number :
- edsair.doi.dedup.....d0e625031397d2722866635543fc5a9e