A xylanase gene was PCR-cloned from Thermoanaerobacterium saccharolyticum and expressed in Escherichia coli. The xylanase (XynA) consisted of a signal peptide, glycoside hydrolase family 10 domains, carbohydrate-binding modules, and surface layer homology domains. It was optimally active at 70-73A degrees C and at pH 5-7. It had enhanced activity with NaCl with optimal activity at 0.4 M but was tolerant up to 2 M NaCl. The thermostable and salt-tolerant properties of this xylanase suggest that it may be useful for industrial applications.