Purification, characterization and specificity of a new GH family 35 galactosidase from Aspergillus awamori.

Vidya, C. H. and Gnanesh Kumar, B. S. and Chinmayee, Cirium V. and Sridevi Annapurna, Singh (2020) Purification, characterization and specificity of a new GH family 35 galactosidase from Aspergillus awamori. International Journal of Biological Macromolecules, 156. pp. 885-895. ISSN 0141-8130

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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.

Item Type:	Article
Uncontrolled Keywords:	Solid state fermentation Galactosidases Broad substrate specificity
Subjects:	600 Technology > 05 Chemical engineering > 04 Fermentation Technology 600 Technology > 08 Food technology > 16 Nutritive value > 05 Enzymes
Divisions:	Dept. of Biochemistry Protein Chemistry and Technology
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	27 Nov 2020 09:15
Last Modified:	27 Nov 2020 09:15
URI:	http://ir.cftri.res.in/id/eprint/14662

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