Cloning, Expression, and Characterization of a New Xylanase from Alkalophilic Paenibacillus sp. 12-11

Abstract

A xylanase gene, xyn7c, was cloned from Paenibacillus sp. 12-11, an alkalophilic strain isolated from the alkaline wastewater sludge of a paper mill, and expressed in Escherichia coli. The full-length gene consists of 1,296 bp and encodes a mature protein of 400 residues (excluding the putative signal peptide) that belongs to the glycoside hydrolase family 10. The optimal pH of the purified recombinant XYN7C was found to be 8.0, and the enzyme had good pH adaptability at 6.5-8.5 and stability over a broad pH range of 5.0-11.0. XYN7C exhibited maximum activity at 55 o C and was thermostable at 50 o C and below. Using wheat arabinoxylan as the substrate, XYN7C had a high specific activity of 1,886 U/mg, and the apparent K m and V max values were 1.18 mg/ml and 1,961 µmol/mg/min, respectively. XYN7C also had substrate specificity towards various xylans, and was highly resistant to neutral proteases. The main hydrolysis products of xylans were xylose and xylobiose. These properties make XYN7C a promising candidate to be used in biobleaching, baking, and cotton scouring processes.

Cloning, Expression, and Characterization of an GHF 11 Xylanase from Aspergillus niger XZ-3S

“…Many kinds of xylanases have been cloned [12][13][14][15][16][17], and expressed in heterologous hosts [13][14][15][16][17][18][19]. Although many xylanase genes have been described from diverse microorganisms, relatively little is known about xylanase gene from Aspergillus niger XZ-3S.…”

C-Terminal proline-rich sequence broadens the optimal temperature and pH ranges of recombinant xylanase from Geobacillus thermodenitrificans C5

“…4), which is far better than that of its wild type xylanase. This increase in thermal stability is far better than most of the bacterial xylanases that are previously reported [36][37][38][39].…”

“…GthC5ProXyl optimal reaction temperature was found to be 70 • C that is found 10 • C higher than that of G. thermodenitrificans C5 wild type xylanase, and 15 • C than Paenibacillus sp. 12-11 [36].…”

Molecular Cloning and Sequencing of AlkalophilicCellulosimicrobium cellulans CKMX1 Xylanase Gene Isolated from Mushroom Compost and Characterization of the Gene Product

“…S14 (Thayat et al 2011), Paenibacillus sp. 12-11 (Zhao et al 2011) and Streptomyces sp. S27 (Li et al 2009).…”