Lactobacillus food grade expression vector pMG36N and preparation method thereof

Abstract

The invention discloses a lactobacillus food grade expression vector pMG36N which does not contain erythrocin resistance gene, introduces a natural food preservative streptococcus lactis peptide Nisinresistance gene nisI as a selection mark. The invention also discloses a preparation method of the lactobacillus food grade expression vector pMG36N. The lactobacillus food grade expression vector pMG36N does not take the resistance gene, i.e. erythrocin and the like, as a screening mark, enhances the safety of lactobacillus and can be used for food production.

Description

technical field [0001] The invention relates to the field of molecular biology, in particular to a lactic acid bacteria food-grade expression vector pMG36N and a preparation method thereof. Background technique [0002] Lactic acid bacteria (LAB) is a kind of food-grade microorganisms recognized as safe (generally regard as safe, GRAS). It includes more than a dozen genera such as Lactococcus lactis, Bifidobacterium and Lactobacillus. The nutritional value of food, improving intestinal environment, improving lactose metabolism, controlling serum cholesterol level, inhibiting the reproduction of pathogenic bacteria, anti-tumor activity and other functions play an extremely important role in food fermentation, medicine and other fields closely related to human life. [0003] Lactococcus lactis, as a model species of lactic acid bacteria, has long been used in the food fermentation industry for the production and preservation of dairy products and as a delivery carrier for hete...

AI Technical Summary

Problems solved by technology

[0004] Most of the traditional lactic acid bacteria expression vectors use antibiotic resistance genes such as erythromycin or chloramphenicol as selection markers, but putting antibiotic resistance genes into the environment or human and animal bodies may bring about hidden dangers of resistance factor transfer. Therefore, from the perspective of food safety, microorganisms containing antibiotic resistance gene markers cannot be used in food production

At present, the food-grade selection markers reported at home and abroad include α-galactosidase gene aga, cadmium resistance gene Cd R , alanine racemase gene ala, etc. Since the above selection markers are not derived from lactic acid bacteria, their application safety will be limited to a certain extent