Project description:Background: Fucoxanthin (FX), a xanthophyll pigment which occurs in marine brown algae with remarkable biological properties, has been proven to be safe for consumption by animals. Although FX has various pharmacological effects including anti-inflammatory, anti-tumor, anti-obesity, antioxidant, anti-diabetic, anti-malarial, and anti-lipid, in vivo protective effect against sepsis has not been reported. In this study, we aimed at evaluation the efficacy of the FX in a model of sepsis mouse. Methods: FX was successfully isolated from Conticribra weissflogii ND-8 for the first time. The FX was identified by thin-layer chromatography (TLC), high-performance liquid chromatography-mass spectrometry (HPLC-MS), and nuclear magnetic resonance (NMR). Animals were randomly divided into 9 groups, including Sham group (mouse received an intraperitoneal injection of normal saline 1.0 ml/kg), FX-treated (0.1-1.0 ml/kg), Lipopolysaccharide (LPS)-treated (20 mg/kg), FX+LPS-treated (0.1-10.0 mg/kg and 20 mg/kg, respectively), and urinastatin groups (104 U/kg). Nuclear factor (NF)-κB activation could be potential treatment for sepsis. NF-κB signaling components were determined by western-blotting. IL-6, IL-1β, TNF-α production, and NF-κB activation were evaluated by ELISA and immunofluorescent staining in vitro. Results: FX was found to decrease the expression of inflammatory cytokines including IL-6, IL-1β, and TNF-α, in a prophylactic manner in the LPS-induced sepsis mouse model. Meanwhile, FX significantly inhibits phosphorylation of the NF-κB signaling pathway induced by LPS at the cellular level and reduces the nuclear translocation of NF-κB. The IC50 for suppressing the expression of NF-κB was 11.08 ± 0.78 μM in the THP1-Lucia™ NF-κB cells. Furthermore, FX also inhibits the expression of inflammatory factors in a dose-dependent manner with the IC50 inhibition of IL-6 production was 2.19 ± 0.70 μM in Raw267.4 macrophage cells. It is likely that the molecules with the ability of targeting NF-κB activation and inflammasome assembly, such as fucoxanthin, are interesting subjects to be used for treating sepsis.
Project description:The production of fucoxanthin and fatty acids in Conticribra weissflogii has been examined, but the role of elements like phosphorus in their mutualistic interactions is not well understood. To fill this gap, our study utilized potassium dihydrogen phosphate (KH2PO4) as a source of phosphorus to examine its impact on the synthesis of fucoxanthin and fatty acids in C. weissflogii. Our findings revealed that at a phosphorus concentration of 10 mg L-1, the cell density (9.5 × 105 cells mL-1), carotenoid concentration (1.67 mg g-1), fucoxanthin concentration (0.91 mg L-1), and fucoxanthin content (1.33 mg g-1) were maximized. Additionally, at a phosphorus concentration of 20 mg L-1, cell dry weight (0.76 ± 0.08 g L-1), total fatty acid content, saturated fatty acids, and unsaturated fatty acids were all at their highest levels, making this concentration optimal for EPA accumulation. In conclusion, manipulating the phosphorus concentration can enhance the levels of fucoxanthin and unsaturated fatty acids in C. weissflogii, offering valuable insights into the co-production of these two high-value compounds within this species.
Project description:We sought to understand the change in the global gene expression profile of the ΔYGP1 strain in comparison with the BGL-6_Kl parental strain. The transcriptome analysis revealed the change in expression of genes involved in cell wall structure, biogenesis, and integrity that might contribute to the improvement of the BGL display efficiency phenotype.
Project description:To solve the problem of low FK520 production by Streptomyces hygroscopicus var. ascomyceticus FS35, PHB synthesis gene phaC and PHB decomposition gene fkbU were co-overexpressed in parent strain FS35 to construct recombinant strain OphaCfkbU. Surprisingly, recombinant strain OphaCfkbU accumulated more biomass than parent strain FS35 in whole fermentation. Therefore, to explore the effect of co-overexpression on the strain growth, comparative transcriptome analysis were carried out between parent strain FS35 and recombinant strain OphaCfkbU. Transcriptome data showed that co-overexpression increased the utilization of sugar sources and stimulated the generation of coenzymes, ribosome, acyl carrier proteins and sulfate donors. This study revealed the internal mechanism of the effect of PHB on strain growth, proving a reference for the role of PHB in other microorganisms.