Abstract:

Milk proteins are the major component in animal milk, which have various biological activities such as easy uptake and digestion, high nutrition, immunity enhancement and antioxidation. The efficient expression of various milk protein components derived from natural milk by genetic engineering and cell factories has become a hot spot and also a technical breakthrough in the field of animal-free milk biosynthesis. Animal-free milk, as a commercially-available high-tech food that is changing our world, has the same nutritional function as natural milk, but does not contain lactose, cholesterol, allergens, contaminated antibiotics and other undesirable components. The animal-free milk production process does not need to breed animals, which can effectively save resources and energy. It is a new model for future dairy production that could reform the traditional farming industry and lead the development of the food industry and cellular agriculture. In this review, we systematically summarize the current status of intellectual property protection of core technologies related to the metabolic reconstruction of model microbial chassis, efficient expression of recombinant milk proteins, and industrialization of animal-free milk products; discuss hot issues such as bottleneck technologies and biosafety challenges in the R&D of animal-free milk products; present the latest development in the combinatorial biosynthesis of milk proteins, man-made flavoring substance additives, sequence modifications for allergen and smart designs for cell factories. At present, the R&D of recombinant milk protein expression and animal-free milk biosynthesis technology in China is still lagging behind, and funds for R&D and venture capital investment for such an emerging business are insufficient. In order to cope with the intensive international competition, we should increase investment in R&D during the 14th Five-Year Plan Period, and strive to break through key technologies and product production processes. On the other hand, the formulation of biosynthetic food commercialization regulations and industrial policies needs to be facilitated. These efforts will provide irreplaceable scientific and technological support for promoting the development of future farming industry and achieving the agricultural "carbon peaking and neutralization" goal in China.

Key words: milk protein, recombinant expression, animal-free milk, combinatorial synthesis, future food

摘要：

乳蛋白是天然动物奶的主要成分，具有高营养、易吸收、增强免疫力、抗氧化等多种生物活性。采用基因工程和细胞工厂等技术手段，高效表达天然奶中的各种乳蛋白组分，已成为当前人造奶生物合成的研发热点和技术难点。人造奶作为一个已商业化面向市场并正在改变世界的新兴科技食品，营养风味与天然牛奶相当，但不含乳糖、胆固醇、抗生素和致敏原等不良因子，其生产过程无需养殖动物，可以有效节约资源与能源，是一种颠覆传统养殖业的未来乳制品生产新模式，将引领未来食品产业和细胞农业发展方向。本文系统总结了模式微生物底盘改造、重组乳蛋白高效表达和人造奶制品产业化等相关核心技术的知识产权保护现状，探讨了目前人造奶制品研发面临的瓶颈技术挑战和生物安全评价等热点问题，介绍了乳蛋白组合表达、风味物质添加、致敏原删除和细胞工厂智造等最新发展动态，为人造奶等未来合成食品产业化提供重要的理论与技术参考。目前我国乳蛋白重组表达与人造奶生物合成技术研发力量相对薄弱，研发资金与风险投资不足。为应对日趋激烈的国际竞争，“十四五”期间我国应加大研发投入，着力突破共性关键技术与产品生产工艺，同时加快制定未来合成食品商业化管理法规与产业政策，为促进我国未来养殖业发展和实现农业碳达峰、碳中和目标提供的科技支撑。

关键词: 乳蛋白, 重组表达, 人造奶, 组合合成, 未来食品