EVALUATION OF RECOMBINANT GLUCOAMYLASE EXPRESSION BY A NATIVE AND α-MATING FACTOR SECRETION SIGNAL IN PICHIA PASTORIS

Raw starch degrading enzyme specially glucoamylase with binding domain (SBD) has great values in the processing industry because it digests particles below gelatinization temperature by releasing glucose from non-reducing ends sequentially. The purpose of study was to measure secretion levels recombinant Pichia pastoris, using α-mating factor signal peptide (α-MF) and native Aspergillus flavus NSH9. NSH9 gene (with without sequences), encoding a pH thermostable an SBD, successfully cloned expressed pastoris produce glucoamylases. constructed plasmids pPICZB_GA2 (having peptides) pPICZαC_GA2 α-MF) were 5144 5356 bp length respectively. Recombinant pichia having α-MF sequence (plasmid, pPICZαC_GA2) gave highest level secretions after 6 days incubation period 0.5% methanol. In conclusion, yeast expression vector is more efficient for heterologous expression/secretions compared its sequences.