Purification and physicochemical characterisation of Aspergillus niger USM F4 β-mannanase
- Author:
Ab Rashid Syarifah
1
,
2
;
Ibrahim Darah
3
;
Che Omar Ibrahim
4
;
Hassan Ramli
5
;
Woei Yenn Tong
6
Author Information
- Publication Type:Journal Article
- Keywords: Mannanase; Palm kernel cake; Physicochemical characterisation; Protein purification
- MeSH: Aspergillus niger; beta-Mannosidase
- From:Malaysian Journal of Microbiology 2020;16(5):396-406
- CountryMalaysia
- Language:English
-
Abstract:
Aims:This present study focused on purification of fungal β-mannanase produced by Aspergillus niger USM F4 and
also physicochemical characterisation of the purified enzyme.
Methodology and results:The purified β-mannanase with a molecular mass of ~47.4 kDa was demonstrated on SDSPAGE gel. The enzyme signified a purification degree of 4-fold, with final specific activity of 196.42 U/mg. It reached an optimum catalytic activity at pH 4.0 and 60 °C. The thermal stability of the enzyme was up to 70 °C and maintained the 50% activity after 30 min at 80 °C. Meanwhile, the pH stability was in the range of pH 3.0-9.0 and a 30 min half-life at pH 10.0. All chemical substances manifested an inhibitory effect on purified β-mannanase, with SDS (28.16 ± 0.05% residual activity) as the strongest inhibitor, followed by cupric ion (Cu2+) (49.51 ± 0.09% residual activity). As a whole, the enzyme displayed a substrate specificity in the order of locust bean gum (LBG) > carboxymethylcellulose > soluble starch > xylan from oat spelt > α-cellulose. Its preference for LBG has generated the Km and Vmax values of 0.20 mg/mL and 9.82 U/mL, respectively.
Conclusion, significance and impact of study:The outcomes of our study offer potential for use at industrial scales, particularly in the oligosaccharides production that involve acid-related activity, wide-ranging temperature and pH stability. - Full text:20.2020my0016.pdf
