PURIFICATION AND CHARACTERIZATION OF AN EXTRACELLULAR ALKALINE PECTATE LYASE FROM BACILLUS SUBTILIS BPLSY 1

B. Al Balaa, R. Esmail, S. Yazaji

Abstract: Pectinases are among the most important enzymes of food and textile industries. Alkaline pectinases are widely used in the vegetable oil extraction, treatment of food industry wastewaters, coffee and tea fermentations, papermaking and textile processing. A newly isolated Bacillus subtilis, designated as BPLSY1, was cultivated for production of pectinases. An extracellular pectate lyase enzyme (EC 4.2.2.2) from the culture supernatant was purified to homogeneity in three steps using acetone precipitation, ion exchange on HiTrap SP and size exclusion chromatography on Superdex 75. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the purified enzyme showed a single protein band with a molecular weight of 42 kDa. The specific activity of purified enzyme was 58.85 U/mg after 9.86 fold purification. The enzyme characteristics were explored by varying the pH and temperatures. The pectate lyase exhibited maximal catalytic activity at a temperature of 60°C and an alkaline pH 9.5. The presence of 0.5 mM of CaCl2 significantly enhanced pectate lyase activity of the purified enzyme. These findings indicate the enzyme to be alkaline pectate lyase and can be used further for various applications.

Keywords: activity; Bacillus subtilis; characterization; pectate lyase; purification

Date published: 2017-10-20