Diatoms exhibit great potential for biofuels, high value-added production from wastewater and promoting carbon neutrality. Fucoxanthin is identified as the main carotenoid in diatoms, which is a photosynthetic pigment with a variety of biological activities and physiological functions. Light quality is essential for microalgal growth, photosynthesis and intracellular metabolism, and microalgal cells often respond to the effects of light to regulate their biochemical makeup. Therefore, goal of this research was to develop a strategy for altering light quality and intensity to maximize fucoxanthin generation, in line with the photoresponsive traits of Phaeodactylum tricornutum and to investigate the underlying mechanism based on metabolomics and transcriptomics. Different light qualities, culture strategies, light intensities and light ratios were explored and optimized, and the findings illustrated that the optimal fucoxanthin production was observed when under the red light during the initial phase, followed by a transition to the blue-green mixed light (60μmol m −2 s −1 ) conditions in the subsequent phase. Transcriptome and metabolome analyses showed that the light shift strategy provided sufficient energy and precursors for cell growth and fucoxanthin accumulation by enhancing the EMP pathway, TCA cycle, and light-harvesting complex in photosynthetic system. The present study provides a feasible strategy and mechanism to customize the light quality regulatory strategy to enhance biosynthesis of target bioactive compounds, and provides a theoretical basis for further investigation of the regulatory mechanism, which can provide a foundation for microalgal fucoxanthin production.
Fucoxanthin (FX), a marine-origin carotenoid, possesses various physiological activities. However, FX has instability and low water solubility. Encapsulation using nanoparticles effectively addresses these challenges. Nanoparticles loaded with FX were fabricated using a pH-driven method, with pea protein isolate (PPI) and fucoidan (FUC) serving as the raw materials. The optimal nanoparticles were prepared at pH = 7.0 with a PPI:FUC = 1:3, yielding a particle size of 166.60 ± 0.55 nm and a zeta potential of −40.88 ± 0.68 mV. The formation of FX@PPI/FUC nanoparticles were primarily driven by hydrogen bonding and hydrophobic interactions. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and fluorescence spectroscopy were used to research structure of nanoparticle and interaction during the formation. The FX@PPI/FUC nanoparticles demonstrated excellent thermal and pH stability in neutral and alkaline environments, effectively released FX and showcased antioxidant properties. Additionally, a W/O/W FX@PPI-FUC Pickering emulsion was formulated, containing 65 % of the oil phase, which exhibited a favorable particle size of 26.5 ± 0.28 μm and a zeta potential of −67.2 ± 0.94 mV. Furthermore, the FX@PPI-FUC Pickering emulsion demonstrated outstanding thermal and storage stability, indicating its potential for application in functional food.
危险品化学品经营许可证（带存储）