التنقية الجزئية لاستيراز حمض هيدروكسي السيناميك و دراسة فعاليته في اصطناع الاستر الايتيلي لحمض الفيروليك

A partial purification was performed for the fungal hydroxycinnamic acid esterase (HCAE) from Humicola sp. by precipitation using either ammonium sulfate or acetone. The highest activity yield (91%) was obtained after the precipitation by acetone, which was nearly three times higher than the activity yield (30%) measured after the precipitation by ammonium sulfate. The enzyme showed optimal activity at 50 °C and pH 6.5. Enzymatic synthesis of ferulic acid ethyl ester was achieved using the enzyme issued from the precipitation by acetone. The effect of water on the esterification reaction was studied, and the result showed that the highest esterification yield (95.7%) was obtained when the percentage of water was 2% in the reaction mixture