Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China.
Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
Bioresour Technol. 2024 Dec;413:131466. doi: 10.1016/j.biortech.2024.131466. Epub 2024 Sep 12.
Haematococcus lacustris-derived natural astaxanthin has significant commercial value, but stressful conditions alone impair cell growth and reduce the total productivity of astaxanthin in industrial settings. This study used gamma-aminobutyric acid (GABA) to increase biomass, astaxanthin productivity, and tolerance to salinity. GABA under NaCl stress enhanced the biomass to 1.76 g/L, astaxanthin content to 30.37 mg g, and productivity to 4.10 mg/L d, outperforming the control. Further analysis showed GABA enhanced nitrogen assimilation, Ca level, and cellular GABA content, boosting substrate synthesis, energy metabolism, osmoregulation, autophagy, and antioxidant defenses. GABA also activated signaling pathways involving phytohormones, cAMP, cGMP, and MAPK, aiding astaxanthin synthesis. The application of biomarkers (ethylene, salicylic acid, trans-zeatin) and an autophagy inhibitor cooperated with GABA to further enhance the total astaxanthin productivity under NaCl stress. Combining GABA with 25 μM salicylic acid maximized astaxanthin yield at 4.79 mg/L d, offering new strategies for industrial astaxanthin production.
盐度胁迫下，GABA 提升盐生杜氏藻生物量、虾青素产量和耐盐性。GABA 在 NaCl 胁迫下，将生物量提升至 1.76 g/L，虾青素含量提升至 30.37 mg/g，产率提升至 4.10 mg/L/d，优于对照组。进一步分析表明，GABA 增强了氮同化、Ca 水平和细胞内 GABA 含量，促进了底物合成、能量代谢、渗透压调节、自噬和抗氧化防御。GABA 还激活了涉及植物激素、cAMP、cGMP 和 MAPK 的信号通路，有助于虾青素的合成。生物标志物（乙烯、水杨酸、玉米素核苷）和自噬抑制剂的应用与 GABA 协同作用，进一步提高了 NaCl 胁迫下虾青素的总产量。将 GABA 与 25 μM 水杨酸结合使用，虾青素产量最大，达到 4.79 mg/L/d，为工业虾青素生产提供了新策略。
