Food-grade gene transformation system constructed in Lactobacillus plantarum using a GlmS-encoding selection marker

Area of Science:

• Microbiology
• Molecular Biology
• Biotechnology

Background:

• Food-grade gene expression systems in lactic acid bacteria are crucial for producing functional proteins and for product testing, avoiding the need for antibiotics.
• The development of novel selection markers is essential for expanding the utility of these systems.

Purpose of the Study:

• To develop a novel food-grade genetic transformation system for Lactobacillus plantarum WCFS1.
• To establish a new selection marker using the glucosamine-6-phosphate synthase gene (glmS).

Main Methods:

• A food-grade vector, pSIPH497, was constructed by replacing the erythromycin resistance gene with the L. plantarum glmS gene under the control of the PldhL promoter.
• The selection efficiency and stability of the new glmS-based vector were compared to traditional antibiotic resistance markers.
• The functionality of the system for foreign protein production was assessed using mCherry as a reporter gene.

Main Results:

• The glmS-based vector demonstrated selection efficiency and stability comparable to erythromycin resistance-based plasmids.
• The system proved feasible for the production of foreign proteins, as indicated by mCherry expression.
• This study successfully established a food-grade host/vector system for Lactobacillus plantarum.

Conclusions:

• The developed food-grade system offers an effective and safe method for applying lactic acid bacteria in the food and medical industries.
• This strategy provides a valuable approach for creating food-grade selection markers in other host/vector systems.
• The new system enhances the safety and applicability of genetically modified lactic acid bacteria.