Carbon partitioning in lipids synthesized by Chlamydomonas reinhardtii when cultured under three unique inorganic carbon regimes
Carbon partitioning in lipids synthesized by Chlamydomonas reinhardtii when cultured under three unique inorganic carbon regimes
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DOI：
10.1016/j.algal.2014.08.001
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发表时间：
2014-07-01
影响因子：
5.1
通讯作者：
Gerlach, Robin
中科院分区：
文献类型：
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作者：
Lohman, Egan J.;Gardner, Robert D.;Gerlach, Robin
无机碳是微藻脂质生物合成的基本成分。了解溶解无机碳（DIC）的浓度和形态如何影响微藻中的脂质代谢，可能有助于研究人员优化这些高价值代谢物的生产。使用相对直接的方法定量游离脂肪酸（FFA），单-（MAG），二-（DAG），三酰基甘油酯（TAG），和总细胞脂肪酸（FAME），脂质谱随着时间的推移建立了莱茵衣藻生长在三个独特的无机碳制度。具体地，将用大气空气鼓泡的培养物与用5%CO2（v/v）鼓泡的培养物和在培养基氮耗尽之前补充50 mM NaHCO 3的培养物进行比较。在培养基中氮耗尽之前，所有三种条件均表现出相似的脂质谱，FFA和MAG是主要的脂质代谢产物。然而，这些前体在氮耗尽后迅速重新分配到DAG和随后的TAG中。C-16 DAG在任何处理中都没有显著积累，而C-18 DAG含量在指数生长期和稳定期都增加。C-16和C-18 TAG在氮耗尽后开始积累，其中C-16 TAG对总TAG含量的贡献最大。C-16脂肪酸在氮耗尽后表现出向饱和C-16脂肪酸的转变。结果提供了深入了解无机碳分配到脂质化合物和生物体的脂质代谢的变化，由于N-耗尽培养和无机碳源的可用性。这里提出的方法和研究结果可以适用于其他生物具有高度的工业相关性。(C)2014年爱思唯尔B。版权所有© 2016
Inorganic carbon is a fundamental component for microalgal lipid biosynthesis. Understanding how the concentration and speciation of dissolved inorganic carbon (DIC) influences lipid metabolism in microalgae may help researchers optimize the production of these high value metabolites. Using relatively straight forward methods for quantifying free fatty acids (FFAs), mono- (MAG), di- (DAG), tri-acylglycerides (TAG), and total cellular fatty acids (FAME), lipid profiles over time were established for Chlamydomonas reinhardtii when grown under three unique inorganic carbon regimes. Specifically, cultures sparged with atmospheric air were compared to cultures which were sparged with 5% CO2 (v/v) and cultures supplemented with 50 mM NaHCO3 just prior to medium nitrogen depletion. All three conditions exhibited similar lipid profiles prior to nitrogen depletion in the medium, with FFA and MAG being the predominant lipid metabolites. However, these precursors were quickly reallocated into DAG and subsequently TAG after nitrogen depletion. C-16 DAG did not accumulate significantly in any of the treatments, whereas the C-18 DAG content increased throughout both exponential growth and stationary phase. C-16 and C-18 TAG began to accumulate after nitrogen depletion, with C-16 TAG contributing the most to overall TAG content. C-16 fatty acids exhibited a shift towards saturated C-16 fatty acids after nitrogen depletion. Results provide insight into inorganic carbon partitioning into lipid compounds and how the organism's lipid metabolism changes due to N-deplete culturing and inorganic carbon source availability. The methodologies and findings presented here may be adapted to other organisms with high industrial relevance. (C) 2014 Elsevier B. V. All rights reserved.