The Role of Calcium Ions to Improve Activity of Chitinase Isolated from Vibrio sp.

Abstract

Chitinase (EC 3.2.1.14) plays a crucial role in chitin degradation, specifically breaking down the 1→4 β-glycosidic bonds of N-acetyl-D-glucosamine (GlcNAc) to produce its mono- or oligomers. This study aims to study the characteristics of chitinase from Vibrio sp. (isolated from tiger shrimp in Indonesia) and explore the role of calcium ions (Ca2+) in increasing chitinase activity. The optimum condition for chitinase activities is pH 7.5, 45 oC of temperature, and 120 min of incubation time. The enzyme activity parameters such as Km and Vmax values were calculated by varying the concentration of Ca2+, namely: 0 %; 0.2 %; 0.4 %; 0.6%; 0.8 %. The final product of the chitinase reaction, the GlcNAc, is then used to measure the enzyme activity based on the Somogyi-Nelson method. The results showed that chitinase isolated from Vibrio sp. has increasing activity with the addition of Ca2+. Without the addition of Ca2+, the Km and Vmax of chitinase were 7.781 nmol mL-1 and 0.066 nmol min-1, respectively. The treatment of 0.4 % Ca2+ shows optimum activity with the Km and Vmax at 6.723 nmol mL-1 and 0.079 nmol min-1, respectively. The results showed the potential use of Ca2+ as a chitinase activator to fulfill demands for energy-efficient and economically profitable chitinase usage.