TY - JOUR
T1 - A cold-adapted endoglucanase from camel rumen with high catalytic activity at moderate and low temperatures
T2 - an anomaly of truly cold-adapted evolution in a mesophilic environment
AU - Khalili Ghadikolaei, Kamran
AU - Gharechahi, Javad
AU - Haghbeen, Kamahldin
AU - Akbari Noghabi, Kambiz
AU - Hosseini Salekdeh, Ghasem
AU - Shahbani Zahiri, Hossein
PY - 2018/3
Y1 - 2018/3
N2 - 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.
AB - 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.
KW - Endoglucanase
KW - Cold-adapted
KW - Camel rumen
KW - Metagenome
KW - Catalytic activity
UR - http://www.scopus.com/inward/record.url?scp=85041675200&partnerID=8YFLogxK
U2 - 10.1007/s00792-018-0999-6
DO - 10.1007/s00792-018-0999-6
M3 - Article
C2 - 29330650
AN - SCOPUS:85041675200
SN - 1431-0651
VL - 22
SP - 315
EP - 326
JO - Extremophiles
JF - Extremophiles
IS - 2
ER -