New Mexico State University Outdoor Cultivation Testbeds, Rapid Analysis (Mass Spectral peak list-Soy Oil_neg)

Cultivation of microalgae has the potential to provide lipid-derived feedstocks for conversion to liquid transportation fuels. Lipid extracts from microalgae are significantly more complex than those of traditional seed oils, and their composition changes significantly throughout the microalgal growth period. With three-acyl side chains per molecule, triglycerides (TAGs) are an important fuel precursor, and the distribution of acyl-chain composition for TAGs has significant impact on fuel properties and processing. Therefore, determination of the distribution of microalgal TAG production is needed to assess the value of algae extracts designed for fuel production and to optimize strain, cultivation, and harvesting practices. Methods utilized for TAG speciation commonly involve complicated and time-consuming chromatographic techniques. We present a method for TAG speciation and quantification based on direct-infusion mass spectrometry, which provides rapid characterization of TAG profiles without chromatographic separation. Specifically, we utilize Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to provide a reference library of TAGs for the microalgae Nannochloropsis sp. that provides the basis for high-throughput TAG quantitation by time-of-flight (TOF) MS. We demonstrate the application of this novel approach for lipid characterization with respect to TAG compound distribution, which informs both immediate and future strain and process optimization strategies.

微藻培养具备为液态交通燃料转化提供脂类原料的潜力。相较于传统种子油，微藻脂类提取物的组成显著更为复杂，且其成分会随微藻生长周期发生显著变化。甘油三酯（TAGs）每个分子含三条酰基侧链，是重要的燃料前体，其酰基链组成分布对燃料性能与加工流程具有显著影响。因此，明确微藻甘油三酯的产出分布，对于评估用于燃料生产的藻提取物价值、优化藻株、培养工艺及采收方案均具有重要意义。当前用于甘油三酯组分分析的方法通常涉及复杂且耗时的色谱技术。本研究提出一种基于直接进样质谱的甘油三酯定性与定量分析方法，无需色谱分离即可快速表征甘油三酯谱图。具体而言，我们利用傅里叶变换离子回旋共振质谱（FT-ICR MS）为微藻*Nannochloropsis* sp.构建甘油三酯参考数据库，以此为基础实现基于飞行时间（TOF）质谱的高通量甘油三酯定量分析。我们验证了该新型方法在针对甘油三酯化合物分布的脂类表征中的应用效果，可为当前及未来的藻株与工艺优化策略提供参考依据。