A cold-adapted endoglucanase from camel rumen with high catalytic activity at moderate and low temperatures

an anomaly of truly cold-adapted evolution in a mesophilic environment

Kamran Khalili Ghadikolaei, Javad Gharechahi, Kamahldin Haghbeen, Kambiz Akbari Noghabi, Ghasem Hosseini Salekdeh, Hossein Shahbani Zahiri*

*Corresponding author for this work

Research output: Contribution to journalArticle

7 Citations (Scopus)


Endoglucanases are important enzymes in plant biomass degradation. They have current and potential applications in various industrial sectors including human and animal food processing, textile, paper, and renewable biofuel production. It is assumed that the cold-active endoglucanases, with high catalytic rates in moderate and cold temperatures, can improve the cost-effectiveness of industrial processes by lowering the need for heating and, thus, energy consumption. In this study, the endoglucanase CelCM3 was procured from a camel rumen metagenome via gene cloning and expression in Escherichia coli BL21 (DE3). The maximum activity of the enzyme on carboxymethyl cellulose (CMC) was obtained at pH 5 and 30 °C with a Vmax and Km of 339 U/mg and 2.57 mg/ml, respectively. The enzyme with an estimated low melting temperature of 45 °C and about 50% activity at 4 °C was identified to be cold-adapted. A thermodynamic analysis corroborated that CelCM3 with an activation energy (Ea), enthalpy of activation (ΔH), and Gibb’s free energy (ΔG) of, respectively, 18.47 kJ mol−1, 16.12 kJ mol−1, and 56.09 kJ mol−1 is a cold-active endoglucanase. In addition, CelCM3 was tolerant of metal ions, non-ionic detergents, urea, and organic solvents. Given these interesting characteristics, CelCM3 shows promise to meet the requirements of industrial applications.

Original languageEnglish
Pages (from-to)315-326
Number of pages12
Issue number2
Publication statusPublished - Mar 2018
Externally publishedYes



  • Endoglucanase
  • Cold-adapted
  • Camel rumen
  • Metagenome
  • Catalytic activity

Cite this