Genetically engineered strain for producing porcine myoglobin and food-grade fermentation and purification thereof

A genetically engineered P. pastoris strain comprising an expression vector, wherein the expression vector comprises a nucleotide sequence encoding an amino acid sequence of porcine myoglobin which is set forth in SEQ ID NO:13;

• wherein the nucleotide sequence is SEQ ID NO:1;
• wherein the expression vector comprises a glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter or a G1 promoter,
• wherein the nucleotide sequence encoding the G1 promoter is set forth in SEQ ID NO:
• 12;
• and
• wherein the expression vector comprises a signal peptide nucleotide sequence selected from the group consisting of:
• an α-factor signal peptide nucleotide sequence set forth in SEQ ID NO:44,
• an α-amylase signal peptide nucleotide sequence set forth as SEQ ID NO:2,
• a glucoamylase signal peptide nucleotide sequence set forth as SEQ ID NO:3,
• an inulinase signal peptide nucleotide sequence set forth as SEQ ID NO:4,
• an invertase signal peptide nucleotide sequence set forth as SEQ ID NO:5,
• a lysozyme signal peptide nucleotide sequence set forth as SEQ ID NO:6,
• a killer protein signal peptide nucleotide sequence set forth as SEQ ID NO:7,
• a serum albumin signal peptide nucleotide sequence set forth as SEQ ID NO:8,
• an sp23 signal peptide nucleotide sequence set forth as SEQ ID NO:9,
• an nsB signal peptide nucleotide sequence set forth as SEQ ID NO:
• 10, and
• a pre-Ost1-alpha factor signal peptide nucleotide sequence set forth as SEQ ID NO:11.