Presentation Information
[4DSP-02]Carbon source–dependent regulation of membrane vesicle production in Limosilactobacillus antri
○Shino Yamasaki-Yashiki1, Hana Honda1, Yoshio Katakura1 (1. Kansai University (Japan))
Keywords:
Extracellular vesicle,Lactic acid bacteria,Lipoteichoic acid,Immunomodulatory effect
[Purpose] Membrane vesicles (MVs) are nanosized (20–400 nm) extracellular particles that are released by bacteria. MVs carry diverse cellular components, including nucleic acids, proteins, and lipids and function in intercellular communication and host immune modulation. We previously demonstrated that MVs produced by Limosilactobacillus antri JCM 15950 enhance immunoglobulin A production involved in mucosal defense via lipoteichoic acid (LTA). However, low productivity and complex purification remain major challenges for the practical application of MVs. This study aimed to determine whether carbon sources regulate MV production and LTA content in order to enhance the yield of LTA-enriched MVs.
[Methods] L. antri JCM 15950 was cultured anaerobically at 37°C for 96 h in De Man, Rogosa, and Sharpe medium supplemented with ten distinct carbon sources (0.66 mol C/L). MVs were isolated from the culture supernatants by ultracentrifugation (150,000 × g, 2 h) and lipid content was quantified using FM4-64 fluorescence. Particle concentration and size distribution were analyzed by nanoparticle tracking analysis, and LTA was assessed by western blotting using an anti-LTA antibody. Artificial MVs were generated from maltose-grown cells via protoplast formation, followed by membrane extrusion.
[Results] Carbon sources markedly influenced MV productivity and LTA content. Among the ten tested carbon sources, maltose induced the most pronounced increase in MV production, with a six-fold increase per cell compared with glucose, whereas fructose increased production 3.3-fold, and xylose reduced it to approximately one-third. Notably, maltose simultaneously maximized MV production and LTA content per particle. In contrast, xylose enhanced the LTA content but markedly suppressed MV production, indicating differential effects on MV quantity and cargo composition. Even under maltose conditions, only ~10% of the total membrane lipids are released as naturally secreted MVs. Artificial MV preparation from maltose-grown cells increased particle yield per culture volume and cultivation time by approximately 25-fold relative to natural MV production.
[Discussion] The coordinated increase in MV production and LTA content under maltose conditions suggests a link between carbon metabolism and MV production. These findings raise the possibility that carbon source-dependent metabolism may influence the structural properties of the cell envelope, including both the cell wall and cytoplasmic membrane, both of which are associated with MV release. However, even under favorable conditions, natural secretions utilize only a limited fraction of membrane resources, suggesting that MV release may be subject to inherent constraints.
[Conclusion] Carbon source-dependent metabolic regulation significantly affects MV productivity and LTA content in L. antri. Maltose provided the highest MV productivity and LTA content among the tested carbon sources, and artificial preparation provided an effective strategy for overcoming the low yield of natural MV secretion. These findings provide a practical strategy for enhancing MV yield and support their scalable production for functional applications.
[Methods] L. antri JCM 15950 was cultured anaerobically at 37°C for 96 h in De Man, Rogosa, and Sharpe medium supplemented with ten distinct carbon sources (0.66 mol C/L). MVs were isolated from the culture supernatants by ultracentrifugation (150,000 × g, 2 h) and lipid content was quantified using FM4-64 fluorescence. Particle concentration and size distribution were analyzed by nanoparticle tracking analysis, and LTA was assessed by western blotting using an anti-LTA antibody. Artificial MVs were generated from maltose-grown cells via protoplast formation, followed by membrane extrusion.
[Results] Carbon sources markedly influenced MV productivity and LTA content. Among the ten tested carbon sources, maltose induced the most pronounced increase in MV production, with a six-fold increase per cell compared with glucose, whereas fructose increased production 3.3-fold, and xylose reduced it to approximately one-third. Notably, maltose simultaneously maximized MV production and LTA content per particle. In contrast, xylose enhanced the LTA content but markedly suppressed MV production, indicating differential effects on MV quantity and cargo composition. Even under maltose conditions, only ~10% of the total membrane lipids are released as naturally secreted MVs. Artificial MV preparation from maltose-grown cells increased particle yield per culture volume and cultivation time by approximately 25-fold relative to natural MV production.
[Discussion] The coordinated increase in MV production and LTA content under maltose conditions suggests a link between carbon metabolism and MV production. These findings raise the possibility that carbon source-dependent metabolism may influence the structural properties of the cell envelope, including both the cell wall and cytoplasmic membrane, both of which are associated with MV release. However, even under favorable conditions, natural secretions utilize only a limited fraction of membrane resources, suggesting that MV release may be subject to inherent constraints.
[Conclusion] Carbon source-dependent metabolic regulation significantly affects MV productivity and LTA content in L. antri. Maltose provided the highest MV productivity and LTA content among the tested carbon sources, and artificial preparation provided an effective strategy for overcoming the low yield of natural MV secretion. These findings provide a practical strategy for enhancing MV yield and support their scalable production for functional applications.
Comment
To browse or post comments, you must log in.Log in