Purification of bacterial lipase by ion-exchange chromatography A column (size 12£2cm, VtD36.7 cm3) was packed with DEAE–Cellulose (Sigma Chemical, USA). The matrix was activated sequentially with 0.1N HCl and 0.1N NaOH. Subsequently, column was equilibrated with 0.02M phosphate buffer (pH 7.4). The crude enzyme (2 ml of enzyme concentrated by lyophilization 40.2mg protein) after dialysis against 0.005 M phosphate buffer (pH 7.5) was loaded on the column.