High-level production and characterization of a novel β-1, 3-1, 4-glucanase from Aspergillus awamori and its potential application in the brewing industry. (May 2020)

• Record Type: Journal Article
• Authors: Liu, Xueqiang; Jiang, Zhengqiang; Ma, Shuai; Yan, Qiaojuan; Chen, Zixian; Liu, Haijie
• Is Part Of: Process biochemistry. Volume 92(2020)
• Page Start: 252
• Page End: 260
• Publication Date: 2020-05
• Subjects: Aspergillus awamori -- β-1, 3-1, 4-Glucanase -- Brewing industry -- High-level production; Biochemical engineering -- Periodicals; Biotechnology -- Periodicals; Biochemistry -- periodicals; Biotechnology -- periodicals; Chemical Engineering -- periodicals; Génie biochimique -- Périodiques; Biotechnologie -- Périodiques; Biochemical engineering; Biotechnology; Periodicals; 660.63
• DOI: 10.1016/j.procbio.2020.01.017
• Languages: English
• ISSNs: 1359-5113

Abstract

Graphical abstract: Highlights: A novel β-1, 3-1, 4-glucanase gene ( AaBglu12A ) from Aspergillus awamori was expressed in Pichia pastoris . The highest β-1, 3-1, 4-glucanase activity of 159, 500 U/mL was produced in 5-L fermentor. AaBglu12A was an acid tolerant enzyme. The enzyme exhibited strict substrate specificity towards various β-1, 3-1, 4-glucans. AaBglu12A improved mashing performance of filtration rate and viscosity reduction. Abstract: A novel β-1, 3-1, 4-glucanase gene ( AaBglu12A ) from Aspergillus awamori was extracellularly expressed in Pichia pastoris . AaBglu12A showed amino acid identity of 96 % with a glycoside hydrolase family 12 cellulase from A. kawachii and 48 % with a β-1, 3-1, 4-glucanase from Magnaporthe oryzae . The highest β-1, 3-1, 4-glucanase activity of 159, 500 ± 500 U/mL with protein concentration of 31.7 ± 0.3 g/L was achieved in a 5-L fermentor. AaBglu12A was purified until homogeneous with recovery yield of 92 %. Its maximal activity was found at 55 °C and pH 5.0. The enzyme was stable up to 60 °C and within the pH range of 2.0-9.0. It also demonstrated strict substrate specificity towards oat- and barley-glucans as well as lichenan. The K m values for oat-, barley-glucans, and lichenan were 2.82, 3.51, and 2.53 mg/mL, respectively. The V max values for oat-, barley-glucans, and lichenan were 12, 068, 10, 790, and 7236 μmol/min·mg, respectively. AaBglu12A hydrolyzed oat- and barley-β-glucans to produce tetra- and tri-saccharides. However, lichenan was hydrolyzed to yield trisaccharides as the main end product. The addition of AaBglu12A to the mashing process substantially decreased filtration time by 34.5 % and viscosity by 9.6 %. Therefore, the high-level production of AaBglu12A might be a promising strategy for the brewing industry owing to its favorable properties.