A novel bacterial isolate with polysaccharides degrading activity was identified as Paenibacillus sp., andnamed Paenibacillus sp. A59. Even though it is a strict mesophile, optimal xylanase activity of the crudeenzymatic extract was achieved between 50 ◦C and 70 ◦C and more than 60% of the activity was retainedafter incubation for 48 h at 50 ◦C, indicating thermotolerance of the enzymes involved. The extract wasalso active on pre-treated sugarcane residue (SCR) and wheat straw, releasing xylobiose and xylose asthe main products, therefore confirming its predominantly xylanolytic activity. By zymograms and massspectrometry of crude enzymatic extracts of xylan or SCR cultures, a 32 kDa GH10 beta- 1,4- endoxylanasewith xylanase and no CMCase activity was identified.