Biochemical properties and application of a novel β-1,3-1,4-glucanase from Paenibacillus barengoltzii

- A novel β-1,3-1,4-glucanase gene (PbBglu16A) from Paenibacillus barengoltzii was expressed.
- PbBglu16A was purified and biochemically characterized.
- PbBglu16A was an endo-β-1,3-1,4-glucanase with strict substrate specificity.
- PbBglu16A has great potential in β-gluco-oligosaccharides production.

A novel endo-β-1,3-1,4-glucanase gene (PbBglu16A) was cloned from Paenibacillus barengoltzii and heterogeneously expressed in Escherichia coli. The recombinant β-1,3-1,4-glucanase (PbBglu16A) was purified to homogeneity with a recovery yield of 78.6% and a specific activity of 431.8 U mg−1. The molecular mass of PbBglu16A was estimated to be 44.0 kDa by SDS-PAGE. The optimal pH and temperature of PbBglu16A were 6.0 and 55 °C, respectively. The enzyme was stable within pH 3.5-9.0 and up to 55 °C. PbBglu16A exhibited high substrate specificity towards barley β-glucan, oat β-glucan and lichenin. PbBglu16A showed an endo-type cleavage pattern and hydrolyzed endogenous enzyme-deactivated oat bran into β-gluco-oligosaccharides with a yield of 7.0%, which mainly consisted of trioligosaccharide and tetraoligosaccharide. Further, PbBglu16A could promote mashing with a reduced filtration time (14.0%) and viscosity (3.4%). Thus, PbBglu16A might be a promising candidate for the production of β-gluco-oligosaccharides and in brewing industry.