Purification, characterization and application of xylanase produced from Aspergillus foetidus MTCC 4898 by solid state fermentation

The present investigation describes purification, characterization and application of xylanase enzyme produced from Aspergillus foetidus MTCC 4898 by solid state fermentation. An extracellular xylanase produced by solid state fermentation was purified by ammonium sulphate precipitation followed by CMsepharose cation exchange chromatography using and sephadex G-100 gel filtration chromatography. The purification methods gave 38% xylanase recovery. The purified xylanases was characterized and then evaluated for its hydrolytic efficiency using the xylan as a hemicellulosic substrate. The optimum temperature and pH of this purified enzyme was found to be 50°C and 5.5 respectively. The purified xylanase exhibited Km and V max values of 28.88 mg/ml and 25.97μmol/min/mg respectively. The hydrolytic efficiency of purified xylanases was investigated with 2% w/v of birchwood xylan as a substrate using enzyme loading of 18.2 xylanase units/g. The results indicated release of 94.5% of xylose monomers from the xylan which was used as substrate. Further a significant(98%) retention of xylanases activity was observed after 13 hours of enzymatic reaction.