Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China; Shenzhen Key Laboratory of Marine Microbiome Engineering, Shenzhen University, Shenzhen 518060, China; Institute for Food & Bioresource Engineering, College of Engineering, Peking University, Beijing 100871, China.
Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China; Shenzhen Key Laboratory of Marine Microbiome Engineering, Shenzhen University, Shenzhen 518060, China.
Bioresour Technol. 2020 Jul;308:123306. doi: 10.1016/j.biortech.2020.123306. Epub 2020 Apr 4.
To improve lipid and astaxanthin productivity without compromising biomass during the whole cultivation period, carbon-dependent kinetics involving nitrogen stress was applied under excess light to elevate intracellular carbon availability and metabolic activity of Chromochloris zofingiensis. Results suggested that fed-batch strategy proposed could increase lipid and astaxanthin productivity to 457.1 and 2.0 mg L d, respectively. Biomass productivity at 1084.3 mg L d was comparable with that under suitable condition. Then C tracer-based metabolic flux analysis (C-MFA) demonstrated that central carbon metabolism provided ATP, NADPH and carbon availability for lipid biosynthesis during the strategy. In combination with targeted metabolite analysis, C-MFA revealed that the strategy improved precursor content for lipid biosynthesis and elevated path rate to synthesize C16:0 and C18:0. The enhanced lipid content potentially accounted for the high biomass productivity. Therefore, comprehensively understanding relationships between carbon availability and carbon conversion could precisely design strategy for productivity improvements during cultivation.
为了在整个培养期间提高脂质和虾青素的产量，同时又不影响生物量，在过量光照下施加了依赖碳的动力学氮胁迫，以提高 Chromochloris zofingiensis 的细胞内碳可用性和代谢活性。结果表明，所提出的分批补料策略可以将脂质和虾青素的生产力分别提高到 457.1 和 2.0 mg L d。在 1084.3 mg L d 时的生物量生产力与适宜条件下的生产力相当。然后，基于 C 示踪剂的代谢通量分析（C-MFA）表明，在该策略中，中心碳代谢为脂质生物合成提供了 ATP、NADPH 和碳可用性。结合靶向代谢物分析，C-MFA 表明该策略提高了脂质生物合成的前体含量，并提高了合成 C16:0 和 C18:0 的途径速率。增强的脂质含量可能是高生物量生产力的原因。因此，全面了解碳可用性和碳转化之间的关系，可以在培养过程中精确设计提高生产力的策略。
