Isolasi Identifikasi Bakteri Penghasil Xilanase serta Karakterisasi Enzimnya

<p>Xylanase is an extracellular enzyme produced by<br />microorganisms. This enzyme is able to hydrolise xylane<br />(hemicellulose) to produce xylooligosaccharide and xylose.<br />Thermoalkaliphilic xylanase is an agent that can be used as<br />a substitute in the pulp whitening process instead of chlorine.<br />A study was done to isolate, identificate of bacteria and<br />characterize xylanase. The isolation of xylanase producing<br />bacteria has been done from soil and waste of starch industry.<br />Colonies which produced clearing zone were presumed<br />as xylanolytic bacteria and chosen for further screening.<br />Identification of potential isolate in xylanase production was<br />done using 16S ribosomal RNA sequencing. Isolate Bacillus<br />pumilus RXA-III5 originated from lime or alkaline soil was<br />more potential isolate in xylanase production than other 24<br />isolates. Precipitation of xylanase, that was done using<br />ammonium sulphate followed by dialyzes produced xylanase<br />of a higher specific activity (267.1 U.mg-1) than that using<br />acetone (131.1 U.mg-1) and ethanol (186.65 U.mg-1). Xylanase<br />was done at purification produced three fractions of xylanase.<br />Xylanase characteristics consist of pH and temperature<br />(9 and 50oC), Km and Vmaks value 6 mg.ml-1 and 0.2<br />mol.minute-1, respectively. The Fe2+ was the strongest activetor<br />and Mg2+ was the strongest inhibitor activity. This enzyme<br />was detected as a cellulose-free xylanase. Xylanase is a<br />prospective agent for bio-bleaching of paper.</p>