Purification and characterization of novel, thermostable and non-processive GH5 family endoglucanase from Fomitopsis meliae CFA 2

Endoglucanases from glycoside hydrolase family 5 (GH5) are the key enzymes in degradation of diverse plant polysaccharides. Present study reports purification, characterization and partial sequencing of novel thermostable GH5 family endoglucanase from a newly isolated brown rot fungi Fomitopsis meliae CFA 2. Endoglucanase was purified 34.18 fold with a specific activity of 302.90 U/mg. The molecular weight of the endoglucanase was 37.87 kDa as determined by SDS PAGE. LCMS/MS analysis identified the protein to be a member of GH5_5 family. The temperature and pH optima for endoglucanase activity were 70 degrees C and 4.8, respectively. The enzyme catalyzed the hydrolysis of carboxymethyl-cellulose with a Km of 12.0 mg/ml, Vmax of 556.58 mu mol/min/mg and Kcat of 129.41/sec. The enzyme was stimulated by Zn+2 and K+ metal ions and DTT. Half-life (t(1/2)) for endoglucanase was found to be 11.36 h with decimal reduction time (D) of 37.75 h at 70 degrees C. The activation energy for endoglucanase was found to be 30.76 kJ/mol (50 degrees C-70 degrees C). Looking at the results, the endoglucanase from Fomitopsis meliae CFA 2 seems to be a promising thermostable enzyme which may be applicable in applications like biomass hydrolysis. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A novel thermostable GH5 family endoglucanase from a newly isolated brown rot fungi Fomitopsis meliae CFA 2 was purified, characterized and partially sequenced in this study. The enzyme exhibited high specificity, optimal temperature and pH conditions, and was stimulated by metal ions and DTT. Overall, the endoglucanase showed potential for applications in biomass hydrolysis.