Cloning of Endoglucanase I Gene from Trichoderma longibrachiatum and Its Expression in Pichia pastoris

Abstract:

A cellulase high-yield strain was identified and named as Trichoderma longibrachiatum SSL by ITS sequence identification. The endoglucanase1 gene (eg1) encoding endo-l,4-β-D-glucanase I was amplified by RT-PCR method, which including 1386 bp and encoding 461 amino acid. Sequence analysis showed that: This gene has a more 90% homology with the T. longibrachiatum eg1 gene. The eg1 gene encoding the mature peptide was inserted into the Pichia pastoris expression vector pPIC9K, which resulted in construction of the recombinant expression plasmid, ppic9k-eg1. The ppic9k-eg1 was then introduced into the host Pichia pastoris GS115. After the induction of methanol, extracellular recombinant endoglucanase I from the supernatant of the recombinant Pichia pastoris strain reached 73 U/mL. A clear strengthening of the protein bands, whose molecular weight is about 58 kD, appeared in the SDS-PAGE.

Key words:Molecular marker, Cellulase endoglucanase I, Pichia pastoris, Expression