Recombinant cellobiohydrolase of Myceliophthora thermophila: characterization and applicability in cellulose saccharification

AMB Express

Anica Dadwal¹  Tulasi Satyanarayana²  Shilpa Sharma² 

[1] Department of Biological Sciences & Engineering, Netaji Subhas Institute of Technology (University of Delhi), Azad Hind Fauj Marg, Sector-3 Dwarka, 110078, New Delhi, India;Department of Biological Sciences & Engineering, Netaji Subhas Institute of Technology (University of Delhi), Azad Hind Fauj Marg, Sector-3 Dwarka, 110078, New Delhi, India;Department of Biological Sciences & Engineering, Netaji Subhas University of Technology, Azad Hind Fauj Marg, Sector-3 Dwarka, 110078, New Delhi, India;

关键词: Thermostable cellulose;    Recombinant cellobiohydrolase;    Alkalistable;    Solvent tolerance;    Extremozyme;    Cellulose saccharification;   

DOI  :  10.1186/s13568-021-01311-8

来源: Springer

【 摘 要 】

A codon optimized cellobiohydrolase (CBH) encoding synthetic gene of 1188 bp from a thermophilic mold Myceliophthora thermophila (MtCel6A) was cloned and heterologously expressed in Escherichia coli for the first time. In silico analysis suggested that MtCel6A is a GH6 CBH and belongs to CBHII family, which is structurally similar to Cel6A of Humicola insolens. The recombinant MtCel6A is expressed as active inclusion bodies, and the molecular mass of the purified enzyme is ~ 45 kDa. The rMtCel6A is active in a wide range of pH (4–12) and temperatures (40–100 °C) with optima at pH 10.0 and 60 °C. It exhibits T1/2 of 6.0 and 1.0 h at 60 and 90 °C, respectively. The rMtCel6A is an extremozyme with organic solvent, salt and alkali tolerance. The Km, Vmax, kcat and kcat/Km values of the enzyme are 3.2 mg mL−1, 222.2 μmol mg−1 min−1, 2492 s−1 and 778.7 s−1 mg−1 mL−1, respectively. The product analysis of rMtCel6A confirmed that it is an exoenzyme that acts from the non-reducing end of cellulose. The addition of rMtCel6A to the commercial cellulase mix (Cellic CTec2) led to 1.9-fold increase in saccharification of the pre-treated sugarcane bagasse. The rMtCel6A is a potential CBH that finds utility in industrial processes such as in bioethanol, paper pulp and textile industries.Graphical Abstract

【 授权许可】

CC BY