PARTIAL PURIFICATION OF NEUTRAL PROTEASE FROM A LOCAL ISOLATE OF ASPERGILLUS NIGER VAR. CARBONARIUS TFS1 AND ITS APPALICATION

Abstract

Neutral protease was purified partially from local isolate of Aspergillus niger var. carbonarius TFS1 by two steps ,the first step was the precipitations for ammonium sulfate (25-50% saturated) gave the specific activity was 9471.84 unit/mg protein, purification folds were 2.765 and recovery was 81.3%. The second step by using DEAE–cellulose ion exchange chromatography, the specific activity was 4.298 with 68.70% recovery. The optimum pH for enzyme activity was7and rang of pH stability was 6.5–7.5 while the optimum temperature was 30C and temperature stability was 30-35C. The enzyme was immobilized by absorption on the sawdust and used in the removal hair and bating process alternative to chemicals and imported enzyme used in tanning plant in Zaafaraniya of the General Company for Leather Industries. The immobilize enzyme was tested by engineers specializing in laboratory tanning on the skin of goats. The most efficient in removing hair from the skins of goat leather gave by the enzyme concentration 4500 units/ml after 12 hours. Also The enzyme gave activity in bating process 2109.58 unit/gram (LVU) while the activity of Arabon enzyme was 1935.68 unit/gram (LVU) which used routinely in the tanning factory.