or filtration to separate cells can be used as a crude enzyme solution without any further treatment or it can be concentrated to cause sedimentation with an organic solvent such as acetone and ethanol or to cause precipitation with a salting out agent such as ammonium sulfate to obtain a crude enzyme agent the crude enzyme agent thus obtained can be purified and crystallized by a known method to provide a purified enzyme the crude enzyme agent obtained in the manner described above has the following properties this enzyme acts on powdery chitin chitin flakes colloidal chitin or ethylene glycol chitin to decompose it to produce n acetyl glucosamine c f table 1 shown hereinlater the optimum ph at 37 u00b0 c is 5 5 to 6 0 this enzyme is stable in the ph range of from 3 5 to 8 0 the optimum temperature for the action of this enzyme was 37 u00b0 c at a ph of 5 5 in a three hour reaction at temperatures of 30 u00b0 c or lower the enzyme was stable over a period of 24 hours or longer impurities in the crude enzyme agent can be removed by adsorption chromatography over a chitin column conventional ion exchange chromatography or gel filtration with a biogel whereby a highly purified enzyme agent can be obtained the chitinase produced in accordance with the present invention has the advantageous feature of acting on chitin powder more effectively than conventional enzymes for example commercial chitinase supplied by sigma chemical co produces reducing sugar gradually in 48 hours of reaction while the.