Isolation and Identification of Xylanase Producing Bac- teria and Characterization of Its Enzyme Properties. Nur Richana, Tun T. Irawadi, Anwar Nur, and Khaswar Syamsu. Xylanase is an extracellular enzyme produced by microorganisms. This enzyme is able to hydrolise xylane (hemicellulose) to produce xylooligosaccharide and xylose. Thermoalkaliphilic xylanase is an agent that can be used as a substitute in the pulp whitening process instead of chlor- ine. A study was done to isolate, identificate of bacteria and characterize xylanase. The isolation of xylanase producing bacteria has been done from soil and waste of starch indus- try. Colonies which produced clearing zone were presumed as xylanolytic bacteria and chosen for further screening. Identification of potential isolate in xylanase production was done using 16S ribosomal RNA sequencing. Isolate Bacillus pumilus RXA-III5 originated from lime or alkaline soil was more potential isolate in xylanase production than other 24 isolates. Precipitation of xylanase, that was done using ammonium sulphate followed by dialyzes produced xylana- se of a higher specific activity (267.1 U.mg-1) than that using acetone (131.1 U.mg-1) and ethanol (186.65 U.mg-1). Xylana- se was done at purification produced three fractions of xyla- nase. Xylanase characteristics consist of pH and tempera- ture (9 and 50oC), Km and Vmaks value 6 mg.ml-1 and 0.2 mol.minute-1, respectively. The Fe2+ was the strongest active- tor and Mg2+ was the strongest inhibitor activity. This enzyme was detected as a cellulose-free xylanase. Xylanase is a prospective agent for bio-bleaching of paper.