Recombinant xylanase from Streptomyces coelicolor Ac-738: characterization and the effect on xylan-containing products

Abstract

A xylanase gene was isolated from the genomic DNA of Streptomyces coelicolor Ac-738. The 723-bp full-length gene encoded a 241-amino acid peptide consisting of a 49-residue putative TAT signal peptide and a glycoside hydrolase family-11 domain. The mature enzyme called XSC738 was expressed in Escherichia coli M15[pREP4]. The electrophoretically homogeneous protein with a specific activity of 167 U/mg for beechwood xylan was purified. The pH optimum of XSC738 was at pH 6; a high activity was retained within a pH range of 4.5-8.5. The enzyme was thermostable at 50-60 °C and retained an activity at pH 3.0-7.0. Xylanase XSC738 was activated by Mn²⁺, Co²⁺ and largely inhibited by Cd²⁺, SDS and EDTA. The products of xylan hydrolysis were mainly xylobiose, xylotriose, xylopentaose and xylohexose. Xylotetraose appeared as a minor product. Processing of such agricultural xylan-containing products as wheat, oats, soy flour and wheat bran by xylanase resulted in an increased content of sugars.

Xylanases of Cellulomonas flavigena: expression, biochemical characterization, and biotechnological potential

“…The DNA fragments encoding xylanases were amplified by the PCR technique with primers. PCR, cloning, expression and purification of the proteins were performed as previously described (Lisov et al 2014). Q5 DNA-polymerase (NEB) was used for the xylanases genes amplification.…”

“…Characterization of properties of xylanases was performed as previously described (Lisov et al 2014). …”

“…Experiments were done as described previously (Lisov et al 2014) except that the 75 mM universal buffer was used with pH optimum of the xylanases (i.e. pH 7.0 for CFXyl1 and CFXyl3, and pH 7.5 for CFXyl2 and CFXyl4).…”

Inter domain interactions influence the substrate affinity and hydrolysis product specificity of xylanase from Streptomyces chartreusis L1105

“…A longer active life of the enzyme during hydrolysis will lead to reduced enzyme dosage, thereby making the process cost-effective. It was reported that XSC738 endo-xylanase from thermo-acidophilic S. coelicolor Ac-738 exhibited only 20% of the initial activity at 60°C for 1 h, while about 1% activity was detected for 5 min at 70°C (Lisov et al 2013), and SB-9a from Ziziphus mauritiana at 55°C only maintained 50% of its activity for 10 min (Chivero et al 2001). Temperature analyses of xylanase from S. chartreusis L1105 showed that the maximum activity of purified xynA occurred at 65°C.…”