N-Acetyllactosamine Production Using Lactose-Rich β-Galactosidase Catalysis

The patent replaces chemical synthesis methods with enzymatic synthesis using β-galactosidase. This substitution eliminates the need for harmful chemical reagents and solvents while maintaining production feasibility. The enzymatic method uses biologically safe components (lactose and GlcNAc) as substrates, producing food-safe LacNAc without toxic byproducts.

The patent replaces expensive substrates (UDP-Gal and GlcNAc) with inexpensive alternatives (lactose and GlcNAc). Lactose is a common, low-cost sugar widely available from dairy sources, while GlcNAc can be produced from renewable plant resources. This substitution dramatically reduces raw material costs while maintaining synthesis effectiveness through β-galactosidase catalysis.

The patent replaces the synthetic PNP-Gal substrate with natural lactose as the Gal donor. Lactose is a naturally occurring sugar found in milk and dairy products, making it safe for food applications. This substitution maintains the simplicity of the enzymatic reaction while ensuring the product is suitable for food use, as both substrates (lactose and GlcNAc) are food-safe.

The patent optimizes reaction parameters including substrate concentration ratios (lactose to GlcNAc), pH, temperature, and enzyme amount to achieve high conversion efficiency. By carefully controlling these parameters, the method achieves sufficient LacNAc concentration directly in the reaction mixture, eliminating or reducing the need for additional concentration steps and associated costs.

The patent utilizes GlcNAc's dual role: it serves as both the Gal acceptor substrate and can be derived from renewable plant resources rather than expensive crustacean shells. This approach maintains the high purity and food-grade quality of GlcNAc while reducing dependency on costly sources. The method also optimizes the lactose to GlcNAc ratio to maximize conversion efficiency and minimize waste.