Precision-fermented milk proteins as a model for industrial food biotechnology.

Dairy proteins are among the most nutritionally and functionally valuable proteins used in food, clinical nutrition, and infant nutrition, yet their supply remains structurally linked to livestock production and dairy processing streams. Precision fermentation offers, based on proven technology, a route to produce individual milk proteins independently of animal agriculture while preserving their molecular identity and application potential. Recent advances in host engineering, secretion capacity, and bioprocess optimization have moved recombinant milk proteins from proof-of-concept toward industrial relevance. However, not all milk proteins are equally tractable fermentation targets. In this opinion article, we examine β-lactoglobulin, α-lactalbumin, and caseins through the lens of nutritional value, functionality, manufacturing complexity, and commercial readiness. We argue that future success will depend less on sequence expression alone than on scalable biomanufacturing technology and know-how, post-translational fidelity, and application-driven target prioritization.