Towards the production of recombinant animal myoglobin: Engineering of heme biosynthesis pathway in Pichia pastoris

The hemoproteins myoglobin and hemoglobin are responsible for the meaty flavor and characteristic color of cooked meat. Therefore, their addition to plant-based meat alternatives is considered beneficial. Heme plays an essential role in the function of these proteins. We can take advantage of the naturally occurring heme biosynthesis pathway of P. pastoris to recombinantly produce both hemoglobin and myoglobin in high quantities. The targeted knock-out of four genes in P. pastoris, which are thought to be essential in the heme downregulation and degradation, should allow for higher concentrations of heme and, as a result, also more active hemoproteins. To prove this hypothesis, two model strains were used, the first secreting horseradish peroxidase (HRP) and the second expressing chicken myoglobin (Gg_Mb) intracellularly.