基于代谢组学研究Cupriavidus necator利用餐厨废油为碳源合成PHB的机理

运用代谢组学方法研究Cupriavidus necator在不同培养条件下胞内代谢物的变化，寻找影响Cupriavidus necator合成聚-3-羟基丁酸酯（PHB）的生物标志物并探讨代谢机理。利用气相色谱-质谱法（GC/MS）分析不同pH （6、7、8、9）条件下培养Cupriavidus necator的代谢产物，应用偏最小二乘判别分析（PLS-DA）对代谢组学数据进行统计分析，同时结合代谢网络图分析影响PHB合成的代谢途径。PLS-DA分析结果表明:不同pH条件下，鸟氨酸、延胡索酸、β-D-葡萄糖、戊二酸、肌醇、丁酸、甘氨酸、L-天冬酰胺、d-葡萄糖、L-苏氨酸和缬氨酸11种物质表现出显著差异性。结合PLS-DA和代谢途径分析得出:甘氨酸、鸟氨酸、苏氨酸、天冬酰胺和延胡索酸是影响PHB合成的关键代谢物，这些物质通过TCA循环途径、氨基酸合成代谢以及丙酮酸合成降解等途径影响Cupriavidus necator合成PHB。

MECHANISM OF SYNTHESIZING PHB BY CUPRIAVIDUS NECATOR WITH WASTE COOKING OIL AS THE CARBON SOURCE BASED ON METABOLOMICS ANALYSIS

Metabolomics method based on gas chromatography-mass spectrometry (GC-MS) was used to analyze the intracellular metabolites of Cupriavidus necator to obtain potential metabolic biomarkers and reveal the mechanism of poly-3-hydroxybutyrate (PHB) accumulation. The metabolite levels of bacteria under different pH conditions such as 6, 7, 8 and 9 were investigated. The metabolites data was analyzed by partial least-squares discrimination analysis (PLS-DA), which presented distinct difference between the samples of four different conditions. As the pH changes, 11 substances showed significant differences, including ornithine, fumarate, β-D-glucose, glutaric acid, inositol, butyric acid, glycine, L-asparagine, d-glucose, L-threonine and valine. According to PLS-DA and metabolic pathway analysis, glycine, ornithine, threonine, sparagine and fumaric acid were potential metabolic biomarkers. These metabolites influenced PHB production through the metabolic pathways of TCA cycle pathway, amino acid anabolism and pyruvate synthesis degradation.