Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Midorigaoka, Ikeda, Osaka 563-8577, Japan.
Bioresour Technol. 2013 Jul;140:73-9. doi: 10.1016/j.biortech.2013.04.059. Epub 2013 Apr 25.
To investigate the relationship between the production of poly(3-hydroxybutyrate) (PHB) and metabolic changes during different growth phases, a non-sterile batch fermentation process involving an alkalophilic and halophilic bacterium, Halomonas sp. KM-1, was used. Intracellular metabolites were analyzed using gas chromatography-mass spectrometry to characterize the metabolic profile. Significant changes relating to PHB production were observed in the TCA cycle, lipid-synthesis and amino acid biosynthetic pathways were found to shift dramatically between the exponential growth and stationary phases. During the stationary phase, 17 metabolites were upregulated and a cell dry mass of 17.8 g/L that included 44.8% PHB was observed at 24h in 5% glucose-supplemented cultures, whereas 11 metabolites were upregulated and a cell dry mass of 38.4 g/L that included 73.7% PHB was observed at 36 h in 10% glucose-supplemented cultures. This study provides pattern analysis of metabolite regulation during PHB accumulation, indicating that multicomponent and phase-specific mechanisms are involved.
为了研究聚（3-羟基丁酸酯）（PHB）的产生与不同生长阶段代谢变化之间的关系，采用了一种非无菌分批发酵过程，涉及一种嗜碱嗜盐菌，即盐单胞菌 KM-1。使用气相色谱-质谱联用技术分析细胞内代谢物，以描述代谢特征。在指数生长和静止阶段之间，发现与 PHB 生产相关的 TCA 循环、脂质合成和氨基酸生物合成途径发生了显著变化。在静止阶段，在 5%葡萄糖补充培养物中，24 小时时观察到 17 种代谢物上调，细胞干重为 17.8g/L，其中包括 44.8%的 PHB；而在 10%葡萄糖补充培养物中，11 种代谢物上调，细胞干重为 38.4g/L，其中包括 73.7%的 PHB。本研究提供了 PHB 积累过程中代谢物调节的模式分析，表明涉及多组分和阶段特异性机制。
