Biotechnological production of d-tagatose from lactose using metabolically engineering Lactiplantibacillus plantarum

d-Tagatose is a low-calorie sweetener with health benefits. To produce d-tagatose from lactose, a metabolic engineering Lactiplantibacillus plantarum was constructed. The galactokinase gene galK was inactivated and the original promoter of β-galactosidase gene lacLM was replaced by a strong lactose/galactose-inducible promoter PlacLM-35-10 in Lpb. plantarum WCFS1. Subsequently, the l-arabinose isomerase gene AraA derived from Lactobacillus casei...