Engineering lactobacillus plantarum as a recombinant host platform

Abstract

Lactobacillus plantarum is a versatile lactic acid bacterium recognized for its probiotic properties and long-standing use in fermented foods. While traditional microbial chassis such as E. coli or S. cerevisiae have dominated recombinant bioproduction platforms, their limitations in food-grade and probiotic applications necessitate the development of alternative hosts. L. plantarum, with its GRAS status, genetic malleability, and resilience under gastrointestinal conditions, has emerged as a promising next-generation chassis, especially for the biosynthesis of health-related metabolites. The aim of this study is to engineer L. plantarum WCFS1 as a recombinant host platform for the production of functional molecules, with an emphasis on 2′ fucosyllactose (2′-FL), a key human milk oligosaccharide known for its prebiotic and immunomodulatory benefits. To achieve this, advanced synthetic biology tools such as markerless CRISPR/Cas9 editing, auxotrophic selection strategies, and modular expression systems will be employed to introduce and regulate heterologous gene pathways responsible for 2′-FL biosynthesis. The project will also focus on overcoming strain-specific challenges such as transformation efficiency, plasmid stability, and metabolic balancing within the host. If successful, the engineered L. plantarum strain will serve as a live, food-compatible cell factory capable of producing 2′-FL either in fermenters or directly in situ as part of synbiotic formulations. The outcome of this work is expected to contribute to the growing field of probiotic metabolic engineering, offering a scalable, safe, and consumer-friendly platform for functional food innovation.