Expression and purification of beefy meaty peptide in Pichia pastoris

We established a gene expression process to produce a flavor peptide in Pichia pastoris. The octapeptide Lys-Gly-Asp-Glu-Glu-Ser-Leu-Ala was isolated from beef digested by papain, known as "beefy meaty peptide" (BMP). It was considered a savory seasoning in previous literatures. To produce BMP by microorganisms, BMP expression structures encoding tandem repeats of the octapeptide were designed and cloned in E. coli DH5 alpha, then integrated into the AOXI gene of Pichia pastoris GS115. Clones containing different BMP-gene copies, with 4-copy, 8-copy, 12-copy and 16-copy, were obtained and expressed in Pichia pastoris GS115. For the ease of purification, 6 x His tag was fused to the C-termini of the peptides. As a result, the fusion peptides were successfully purified by His-tag bind affinity resin. The BMP fusion peptides with expected sizes were secreted from the resulting strains of P pastoris GS115.