Deinoxanthin, a xanthophyll derived from Deinococcus species, is a unique organic compound that provides greater antioxidant effects compared to other carotenoids due to its superior scavenging activity against singlet oxygen and hydrogen peroxide. Therefore, it has attracted significant attention as a next-generation organic compound that has great potential as a natural ingredient in a food supplements. Although the microbial identification of deinoxanthin has been identified, mass production has not yet been achieved. Here, we report, for the first time, the development of an engineered extremophilic microorganism, Deinococcus radiodurans strain R1, that is capable of producing deinoxanthin through rational metabolic engineering and process optimization. The genes crtB and dxs were first introduced into the genome to reinforce the metabolic flux towards deinoxanthin. The optimal temperature was then identified through a comparative analysis of the mRNA expression of the two genes, while the carbon source was further optimized to increase deinoxanthin production. The final engineered D. radiodurans strain R1 was able to produce 394 ± 17.6 mg/L (102 ± 11.1 mg/g DCW) of deinoxanthin with a yield of 40.4 ± 1.2 mg/g sucrose and a productivity of 8.4 ± 0.2 mg/L/h from 10 g/L of sucrose. The final engineered strain and the strategies developed in the present study can act as the foundation for the industrial application of extremophilic microorganisms.

Introduction: Deinoxanthin (DX), a carotenoid, has excellent antioxidant and anti-inflammatory properties. However, owing to its lipophilicity, it is unfavorably dispersed in water and has low stability, limiting its application in cosmetics, food, and pharmaceuticals. Therefore, it is necessary to study nanoparticles to increase the loading capacity and stability of DX. Methods: In this study, DX-loaded nanocapsules (DX@NCs) were prepared by nanoprecipitation by loading DX into nanocapsules. The size, polydispersity index, surface charge, and morphology of DX@NCs were confirmed through dynamic light scattering and transmission electron microscopy. The loading content and loading efficiency of DX in DX@NCs were analyzed using high-performance liquid chromatography. The antioxidant activity of DX@NCs was evaluated by DPPH assay and in vitro ROS. The biocompatibility of DX@NCs was evaluated using an in vitro MTT assay. In vitro NO analysis was performed to determine the effective anti-inflammatory efficacy of DX@NCs. Results: DX@NCs exhibited increased stability and antioxidant efficacy owing to the improved water solubility of DX. The in situ and in vitro antioxidant activity of DX@NCs was higher than that of unloaded DX. In addition, it showed a strong anti-inflammatory effect by regulating the NO level in an in vitro cell model. Conclusion: This study presents a nanocarrier to improve the water-soluble dispersion and stability of DX. These results demonstrate that DX@NC is a carrier with excellent stability and has a high potential for use in cosmetic and pharmaceutical applications owing to its antioxidant and anti-inflammatory effects.

Among the microorganisms present in the microbiome of Camellia japonica flowers, extracellular vesicles (EVs) derived from Leuconostoc mesenteroides were isolated to investigate their modulatory effects on moisturizing and barrier-related molecular markers. To identify the function of major proteins in L. mesenteroides DB-21-derived extracellular vesicles (LEVs), Gene Ontology (GO) analysis was performed, revealing ATP binding, ribosomal structural proteins, and metal ion binding as predominant molecular-function categories. These proteomic characteristics provide a molecular context that supports the interpretation of the moisturizing and barrier-related responses observed in this study. To further verify new findings, we performed functional evaluations using in vitro and 3D skin models. LEVs increased the mRNA expression level of HAS3, which encodes hyaluronic acid synthase. In addition, the expression levels of filaggrin and involucrin, key proteins involved in skin barrier formation, increased, and these markers were determined a concentration-dependent increase in a 3D artificial skin model. Also, we confirmed that the expression levels of filaggrin and involucrin, which were reduced by UVB damage, were restored when LEVs were applied. In conclusion, LEVs are effective in enhancing various molecular markers related to the skin barrier function, and these results reveal that they hold promise as next-generation microbiome-based functional ingredients.

Kim YH, et al. J Korean Radiol Soc. 2007 Nov;57(5):479-482. http://dx.doi.org/10.3348/jkrs.2007.57.5.479