Identification and Characterization of a Novel Endo-β-1,4-Xylanase from Streptomyces sp. T7 and Its Application in Xylo-Oligosaccharide Production

Abstract

A xylanase-producing strain, identified as Streptomyces sp. T7, was isolated from soil by our lab. The endo-β-1,4-xylanase (xynST7) gene was found in the genome sequence of strain T7, which was cloned and expressed in Escherichia coli. XynST7 belonged to the glycoside hydrolase family 10, with a molecular mass of approximately 47 kDa. The optimum pH and temperature of XynST7 were pH 6.0 and 60 °C, respectively, and it showed wide pH and temperature adaptability and stability, retaining more than half of its enzyme activity between pH 5.0 and 11.0 below 80 °C. XynST7 showed only endo-β-1,4-xylanase activity without cellulase- or β-xylosidase activity, and it showed maximal hydrolysis for corncob xylan in all the test substrates. Then, XynST7 was used for the production of xylo-oligosaccharides (XOSs) by hydrolyzing xylan extracted from raw corncobs. The maximum yield of the XOS was 8.61 ± 0.13 mg/mL using 15 U/mL of XynST7 and 1.5% corncob xylan after 10 h of incubation at 60 °C. The resulting hydrolysate products mainly consisted of xylobiose and xylotriose. These data indicated that XynST7 might by a promising tool for various industrial applications.

Optimization of Xylooligosaccharides Production by Native and Recombinant Xylanase Hydrolysis of Chicken Feed Substrates

“…At high incubation temperatures and long incubation times, the yield of reducing sugars was enhanced (Figure 7b). Li et al [36] reported a Streptomyces spp. T7 which was used to produce XOSs from corncob xylan at 60 • C, with the highest yield of reducing sugars.…”

Streptomyces at the Heart of Several Sectors to Support Practical and Sustainable Applications: A Review

“…Streptomyces sp. produce xylanases, which are utilized in the pulp and paper industry [90,91] and are also able to break down various agricultural residues such as straw waste and oil cake, resulting in enhanced biogas production [91,92] . The industrial application of certain Streptomyces strains that produce xylanase is presented in Table 4.…”

Research Progress on Lignocellulosic Biomass Degradation Catalyzed by Enzymatic Nanomaterials

“… [18b,32a] Endo‐1,4‐ β ‐d‐xylanase is mainly the internal bond of hydrolyzed xylan. Huang et al [54] . isolated a strain of Streptomyces from laboratory soil, which showed that Streptomyces could express endo‐ β ‐1,4‐xylanase.…”

“…[18b,32a] Endo-1,4-β-d-xylanase is mainly the internal bond of hydrolyzed xylan. Huang et al [54] isolated a strain of Streptomyces from laboratory soil, which showed that Streptomyces could express endo-β-1,4-xylanase. The results showed that the activity of this enzyme was only endo-β-1, 4-xylanase, not cellulase and β-xylosidase, and the hydrolysis rate of corncob was the highest.…”