Háskóli ÍslandsUniversity of IcelandKristjánsdóttir, ÞórdísBosma, Elleke F.Branco dos Santos, FilipeÖzdemir, EmreHerrgård, Markus J.França, LucasFerreira, BrunoNielsen, Alex T.Guðmundsson, Steinn2020-03-182020-03-182019-10-29Kristjansdottir, T., Bosma, E.F., Branco dos Santos, F. et al. A metabolic reconstruction of Lactobacillus reuteri JCM 1112 and analysis of its potential as a cell factory. Microb Cell Fact 18, 186 (2019). https://doi.org/10.1186/s12934-019-1229-31475-2859https://hdl.handle.net/20.500.11815/1611Publisher's version (útgefin grein).Background: Lactobacillus reuteri is a heterofermentative Lactic Acid Bacterium (LAB) that is commonly used for food fermentations and probiotic purposes. Due to its robust properties, it is also increasingly considered for use as a cell factory. It produces several industrially important compounds such as 1,3-propanediol and reuterin natively, but for cell factory purposes, developing improved strategies for engineering and fermentation optimization is crucial. Genome-scale metabolic models can be highly beneficial in guiding rational metabolic engineering. Reconstructing a reliable and a quantitatively accurate metabolic model requires extensive manual curation and incorporation of experimental data. Results: A genome-scale metabolic model of L. reuteri JCM 1112T was reconstructed and the resulting model, Lreuteri_530, was validated and tested with experimental data. Several knowledge gaps in the metabolism were identified and resolved during this process, including presence/absence of glycolytic genes. Flux distribution between the two glycolytic pathways, the phosphoketolase and Embden-Meyerhof-Parnas pathways, varies considerably between LAB species and strains. As these pathways result in different energy yields, it is important to include strain-specific utilization of these pathways in the model. We determined experimentally that the Embden-Meyerhof-Parnas pathway carried at most 7% of the total glycolytic flux. Predicted growth rates from Lreuteri_530 were in good agreement with experimentally determined values. To further validate the prediction accuracy of Lreuteri_530, the predicted effects of glycerol addition and adhE gene knock-out, which results in impaired ethanol production, were compared to in vivo data. Examination of both growth rates and uptake- and secretion rates of the main metabolites in central metabolism demonstrated that the model was able to accurately predict the experimentally observed effects. Lastly, the potential of L. reuteri as a cell factory was investigated, resulting in a number of general metabolic engineering strategies. Conclusion: We have constructed a manually curated genome-scale metabolic model of L. reuteri JCM 1112T that has been experimentally parameterized and validated and can accurately predict metabolic behavior of this important platform cell factory.186eninfo:eu-repo/semantics/openAccessCell factoryGenome-scale metabolic modelLactobacillus reuteriGerlarFrumulíffræðiGenamengiinfo:eu-repo/semantics/articleMicrobial Cell Factories10.1186/s12934-019-1229-3