Lactic acid bacteria are the general name for Gram-positive bacteria that can ferment sugars and produce large amounts of organic acids. They have a long history of application in fermented foods. Lactic acid bacteria are generally considered to be safe strains. The genetic engineering operations of these microorganisms have broad application prospects in food and medicine. Expression vectors are one of the commonly used tools in genetic engineering. Most lactic acid bacteria expression vectors usually use antibiotic resistance genes as selection markers. However, resistance genes have potential metastasis, so food-grade expression vectors need to be developed. Food-grade expression vectors do not contain antibiotic resistance genes and only contain DNA from homologous hosts or generally considered safe organisms. This review introduces the composition of lactic acid bacteria food-grade expression vectors and their common hosts, and summarizes the application of lactic acid bacteria food-grade expression vectors.
