Purification and Characterization of a Thermostable β-Mannanase from Bacillus subtilis BE-91: Potential Application in Inflammatory Diseases.

Lifeng Cheng,Xiangyuan Feng,Ke Zheng,Zhengchu Liu,Shengwen Duan,Qi Yang

doi:10.1155/2016/6380147

Abstract

β-mannanase has shown compelling biological functions because of its regulatory roles in metabolism, inflammation, and oxidation. This study separated and purified the β-mannanase from Bacillus subtilis BE-91, which is a powerful hemicellulose-degrading bacterium using a “two-step” method comprising ultrafiltration and gel chromatography. The purified β-mannanase (about 28.2 kDa) showed high specific activity (79, 859.2 IU/mg). The optimum temperature and pH were 65°C and 6.0, respectively. Moreover, the enzyme was highly stable at temperatures up to 70°C and pH 4.5–7.0. The β-mannanase activity was significantly enhanced in the presence of Mn2+, Cu2+, Zn2+, Ca2+, Mg2+, and Al3+ and strongly inhibited by Ba2+ and Pb2+. K m and V max values for locust bean gum were 7.14 mg/mL and 107.5 μmol/min/mL versus 1.749 mg/mL and 33.45 µmol/min/mL for Konjac glucomannan, respectively. Therefore, β-mannanase purified by this work shows stability at high temperatures and in weakly acidic or neutral environments. Based on such data, the β-mannanase will have potential applications as a dietary supplement in treatment of inflammatory processes.

Highlights

Mannan consists of a series of complex polysaccharides, which are found in the cell wall of marine algae [1]
Konjac glucomannan is a randomly arranged polymer of β1,4-linked glucose and mannose residues at ratio of 1.0 : 1.6. Both the backbones of mannan and Konjac are modified by α-1,6-linked galactosyl residues to form galactomannan and galactoglucomannan, respectively [2]
Β-mannanase (EC 3.2.1.78) is a hemicellulase that attacks the internal glycosidic bonds of mannan backbone to release the condensed β-1,4-manno-oligosaccharides [3]. βmannanases are widely applied in pulp and paper processing [4], feed [5], food [6], pharmaceutical [7], oil, and textile industries [8] to randomly hydrolyze the β-1,4 mannopyranoside linkage in mannan, galactomannan, glucomannan, and galactoglucomannan

Summary

Introduction

Mannan consists of a series of complex polysaccharides, which are found in the cell wall of marine algae [1]. Konjac glucomannan is a randomly arranged polymer of β1,4-linked glucose and mannose residues at ratio of 1.0 : 1.6. Both the backbones of mannan and Konjac are modified by α-1,6-linked galactosyl residues to form galactomannan and galactoglucomannan, respectively [2]. Βmannanases are widely applied in pulp and paper processing [4], feed [5], food [6], pharmaceutical [7], oil, and textile industries [8] to randomly hydrolyze the β-1,4 mannopyranoside linkage in mannan, galactomannan, glucomannan, and galactoglucomannan. It is clarified that β-mannanase with high activity in short fermentation time confers lower costs during the production procedures.

Methods

Results

Conclusion