VOLUME 16 NUMBER 2 (July to December 2023)

PSL%202021 vol14-no01-p12-28-Mikita%20and%20Padlan

SciEnggJ. 2023 16 (2) 354-361
available online: October 23, 2023

*Corresponding author
Email Address: aayanos@up.edu.ph
Date received: March 7, 2023
Date revised: June 17, 2023
Date accepted: August 21, 2023


β-Mannanase from Bifidobacterium adolescentis DSM 20083: Molecular Cloning, Expression, and Biochemical Characterization for Manno-Oligosaccharides Production Using Makapuno

Adonis A. Yanos*1, Louelle Sheryl G. Albia1, Sheryl Lozel B. Arreola1, Thu-Ha Nguyen2, and Dietmar Haltrich2

1Institute of Chemistry, College of Arts and Sciences, University of the
      Philippines Los Baños, College, Laguna 4031, Philippines
2Food Biotechnology Laboratory, Department of Food Science and
     Technology, BOKU - University of Natural Resources and Life Sciences
      Vienna, Austria

KEYWORDS: Bifidobacterium adolescentis, makapuno, mannanase, mannans, manno-oligosaccharides

β-Mannanase has gained increasing interest recently due to its ability to degrade mannan polymers and produce high-value products such as manno-oligosaccharides (MOS). In this work, the tendency of β-mannanase from a human isolate, Bifidobacterium adolescentis DSM 20083, to produce potentially prebiotic MOS by hydrolyzing mannan-rich agricultural substrates such as makapuno (Cocos nucifera L.), a naturally occurring coconut variant, was investigated. A truncated variant of the β-mannanase gene was successfully cloned and heterologously expressed in Escherichia coli BL21(DE3). In SDS-PAGE, the recombinant β-mannanase was apparently homogeneous and had a molecular mass of about 110 kDa. The purified enzyme was found to have a specific activity of 66.1 Uman/mg when locust bean gum was used as substrate. The optimum temperature and pH of activity for the enzyme were obtained at 37 °C and pH 5.3, respectively. Among the cations tested, Co2+ was found to increase enzyme activity by 63%. Kinetic measurements showed Km, vmax, kcat and kcat/Km values of 0.32 ± 0.03 mg/mL, 42.4 ± 1.2 µmol/min-mg, 71.3 ± 1.9 /s and 221 ± 30 mL/mg-s, respectively. Analysis using HPAEC-PAD indicated that using makapuno, the major hydrolysis products of the enzyme are 61-α-D-galactopyranosyl-β-1,4-mannobiose (107 mg/g) and 61-α-D-galactopyranosyl-β-1,4-mannotriose (68.1 mg/g) amounting to 88% of total MOS produced. This study has shown that the β-mannanase from B. adolescentis could be used to produce MOS which could be of interest to the food industry.

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