Engineered Komagataella phaffii boosts EGF production 12.8-fold for cultured meat applications

Cultured meat production requires efficient and cost-effective growth factors like Epidermal Growth Factor (EGF) to stimulate cell proliferation in low-serum conditions. Current recombinant EGF expression methods often face challenges in achieving high yields and secretion efficiency, hindering scalability and economic viability for industrial applications. This gap necessitates optimized production strategies to make cultured meat a more sustainable and accessible alternative to traditional meat. The study addresses this by engineering Komagataella phaffii (a yeast) for enhanced EGF synthesis.

Researchers developed an integrated engineering strategy in Komagataella phaffii to boost recombinant EGF production. This involved signal peptide optimization via truncation of amino acids 57-70 in the α-factor signal peptide, overexpression of the transcription factor Mit1, and sequential gene dosage amplification. The engineered strain's EGF yield was evaluated in shake-flask cultures and scaled up to a 5 L bioreactor. Purified recombinant EGF was then tested for biological activity by assessing its ability to promote porcine skeletal muscle satellite cell proliferation under low-serum conditions.

The engineering strategies significantly enhanced EGF production. Truncation of the α-factor signal peptide increased EGF secretion efficiency from 69.8% to 95.3% and boosted yield from 21.86 mg/L to 36.07 mg/L. Overexpression of Mit1 further improved the yield to 42.44 mg/L.

Sequential gene dosage amplification achieved a remarkable 12.8-fold increase, pushing EGF yield to 280.42 mg/L in shake-flask cultures. When scaled to a 5 L bioreactor, the engineered strain produced 370.05 mg/L of EGF. The purified recombinant EGF demonstrated biological activity, effectively promoting porcine skeletal muscle satellite cell proliferation in low-serum culture conditions, confirming its utility for cultured meat applications.