Expression of cellulose-degrading endoglucanase from bacillus subtilis using PTOLT expression system in Escherichia coli

Abstract

Endoglucanases randomly hydrolyse the cellulose chains by acting upon internal β-1,4-D-glycosidic bonds and are used extensively in industrial applications. In this study, bacterial endoglucanase gene yhfE was obtained by PCR, using primers based on genomic sequences of Bacillus subtilis strains. 1041 bp DNA fragment of yhfE was cloned into Escherichia coli DH5α through the use of pTolT expression plasmid. PCR, restriction enzyme analysis and DNA sequencing were performed in order to confirm the cloning. E. coli BL21-AI cells expressed the yhfE after induction at 0.04% of arabinose concentration for 4 h. The expected 38.7 kDa size yhfE protein after digestion with thrombin of the His-tagged fusion protein (yhfE-TolAIII) was visualized by SDS-PAGE. The yhfE-TolAIII production yield was approximately 82 mg/L. The recombinant yhfE was characterized by MALDI-TOF mass spectrometry and CD analysis.