A Metabolic Reconstruction of Lactobacillus Reuteri and Analysis of Its Potential As a Cell Factory

Lactic acid bacteria (LAB) have long been used by humans in the food industry and is Lactobacillus reuteri one of them. Additionally, L. reuteri is also known to produce several different compounds, with potential biotechnological interest, such as; the antimicrobial compound reuterin, vitamin B12 and 1,3-propanediol, which can be used as a starting material for plastic production. In an attempt to further explore L. reuteri as a cell factory for production of valuable compounds, a genome-scale metabolic model was reconstructed and thoroughly curated and validated using data from the literature and several experimental data sets, including knockout strains. The biomass reaction was built from species specific data when available and alternatively from L. plantarum and L. lactis.
L. reuteri metabolizes glucose via the phosphoketolase pathway. Genome data indicates the absence of a phosphofruktokinase (PFK), which results in an inactive EMP pathway. Model simulations show that PFK does not provide a significant advantage in terms of growth.
A pathway prediction algorithm was used to identify several heterologous pathways for production of 1-propanol. Theoretical yields of 1-propanol were evaluated for multiple carbon sources. The most promising pathways were further optimized in silico by identifying targets for overexpression and knockouts for increased production of 1-propanol.