Biochemical characterization of a noble xylanase from Paenibacillus sp. EC116

In our present study, a new Endo-1,4-β-xylanase (EC 3.2.1.8) was isolated, which belongs to glycosyl hydrolase family 10 member. The new enzyme designated as xynA was expressed for biochemical characterization. The xynA xylanase was identified in Paenibacillus sp. EC116. The novel gene had the size of 2673 base pairs, which correspond to 891 amino acid residues. The expressed enzyme has a size of ~100 kDa. The amino acid sequence was similar to that of endo-1,4-beta-xylanase from Paenibacillus sp. FSL R5-192 (ETT36211.1) (96 % identical). The xylanase has an optimal temperature of 40 °C and the pH optimum of 6.0. The specific activity of the xylanase toward birchwood xylan was about 0.69 μmol min⁻¹ mg⁻¹, the V_max value of 1.639 μmol mg⁻¹ min⁻¹, and the K_m value of 35.1 mg ml⁻¹. The EC116 xylanase was relatively stable up to 60 °C. Xylanase enzymes have numerous industrial applications, which need to meet the specific requirements for each application. We hope that our EC116 xylanase is one of the candidates for commercial applications.