Fertilized egg white as a sustainable growth supplement enhances muscle cell proliferation by driving cell cycle progression in serum-restricted culture.

The resource efficiency of cell-cultured meat, particularly reduced land use, is often positioned as a key advantage over conventional meat production. However, this benefit is offset by the heavy reliance on costly fetal bovine serum (FBS). In this study, a C2C12 myoblast model was employed to evaluate SPF-grade egg components as potential substitutes for FBS in muscle cell culture. An initial CCK-8 screening was conducted to assess unfertilized and fertilized egg fractions (white, yolk, and whole egg). Under 2% FBS conditions, the addition of 0.1 mg/mL fertilized egg white (FW) significantly enhanced cell proliferation, with viability 10%-30% higher over 3 days. The superior viability conferred by FW was further validated by a 30-50% reduction in LDH release and an approximately 20% elevation in ATP activity compared with the serum-limited (2% FBS) control. Cell cycle analysis demonstrated that FW treatment induced an approximately 17% reduction in G0/G1 phase cells and an 8% increase in S phase cells relative to the 2% FBS control, providing direct mechanistic evidence of its growth-promoting effect. Long-term culture performance was monitored over 12 serial passages. While the 2% FBS control exhibited a marked decline from 1.27 × 106/mL to 4.98 × 105/mL, the FW-supplemented group sustained 7.12 × 105/mL, with a slower decline rate and approximately 5% higher viability. This superior performance persisted after cryopreservation, indicating that FW effectively supports population stability and cellular vitality. Overall, these findings suggest that 0.1 mg/mL FW could replace up to 80% of FBS, supporting cost-effective and sustainable cultured meat production.