Biochemical properties and thermal behavior of pectate lyase produced by Pectobacterium carotovorum subsp. carotovorum BR1 with industrial potentials

An extracellular pectate lyase (PL, EC 4.2.2.2) produced by Pectobacterium carotovorum subsp. carotovorum BR1 was purified and characterized with respect to its biochemical properties including the thermodynamic parameters of substrates hydrolysis and thermal behavior. The PL showed higher affinity for polygalacturonic acid (Km, 0.4 g l−1) as compared to 70% methylated pectin (Km, 0.77 g l−1). Nonlinear thermal inactivation curves of PL at 50 and 60 °C, fitted to a three-fraction first-order kinetic model. Furthermore, the thermodynamic parameters of thermal deactivation of purified PL viz. ΔH*, ΔS*, Ed and ΔG* were determined over pH range 6–10 and in presence of different cations. Alkaline pH and Ca2+ ions individually influenced the thermostability of PL at elevated temperatures 60 and 70 °C, based on the thermodynamic parameters. The studies suggested that this alkaline PL can be considered as potential candidate for various applications like pectic waste management, degumming of fibers, food, paper and textile industries.

► Kinetics and thermodynamics parameters of the pectate lyase (PL) were determined. ► Thermal inactivation curves of PL fitted three-fraction first-order kinetic model. ► Alkaline pH and Ca2+ ions favor the thermostability of purified PL at 60 and 70 °C. ► Thermoactive PL has an alkaline pH optimum, low Ea and broad substrate specificity. ► PL could be utilized efficiently as a novel source for industrial applications.