Basile F, Beverly M B, Abbas-Hawks C, Mowry C D, Voorhees K J, Hadfield T L
Department of Chemistry and Geochemistry, Colorado School of Mines, Golden 80401-1887, USA.
Anal Chem. 1998 Apr 15;70(8):1555-62. doi: 10.1021/ac970970d.
Fatty acid methyl esters (FAMEs) were generated in situ, during pyrolysis, from whole-cell bacterial samples and analyzed by mass spectrometry (MS). The FAME profiles obtained by an in situ thermal hydrolysis methylation (THM) step were compared with gas chromatography (GC) and MS analyses of the chemically extracted and methylated fatty acids. This correlation was based on the ability of each technique to differentiate a representative group of 15 bacteria at the species level as predicted by principal component analysis. All three analyses, GC/FAME, pyrolysis-MS/FAME, and in situ THM-MS/FAME differentiated the studied bacterial sample set into three discrete clusters. The bacteria comprising each cluster were the same for all three analyses, showing that taxonomic information of the lipid profiles was preserved in the Py-MS/FAME and in situ THM-MS/FAME analyses of whole cells. Contributions from saturated, unsaturated, cyclopropyl, and branched bacterial fatty acids to the differentiation of microorganisms were identified for all three analyses. The in situ THM-MS/FAME approach is simple, requires small samples (approximately 2 x 10(6) cells/profile), and is rapid, with a total analysis time under 5 min/sample.
脂肪酸甲酯（FAMEs）在热解过程中由全细胞细菌样品原位生成，并通过质谱（MS）进行分析。将原位热水解甲基化（THM）步骤获得的FAME谱与化学提取和甲基化脂肪酸的气相色谱（GC）和MS分析结果进行比较。这种相关性基于每种技术在主成分分析预测的物种水平上区分15种代表性细菌的能力。气相色谱/脂肪酸甲酯（GC/FAME）、热解-质谱/脂肪酸甲酯（pyrolysis-MS/FAME）和原位THM-质谱/脂肪酸甲酯（in situ THM-MS/FAME）这三种分析方法都将所研究的细菌样品集分为三个离散的簇。对于所有三种分析，每个簇中的细菌都是相同的，这表明在全细胞的热解质谱/脂肪酸甲酯（Py-MS/FAME）和原位THM-质谱/脂肪酸甲酯（in situ THM-MS/FAME）分析中，脂质谱的分类信息得以保留。对于所有三种分析，都确定了饱和、不饱和、环丙基和支链细菌脂肪酸对微生物分化的贡献。原位THM-质谱/脂肪酸甲酯方法简单，所需样品量小（约2×10⁶个细胞/谱），且速度快，每个样品的总分析时间不到5分钟。
