热纤梭菌中心代谢产物的归属及初步代谢组分析

Metabolomic Analysis of Clostridium thermocellum

热纤梭菌(Clostridium thermocellum)是一种能够高效利用木质纤维素的嗜热厌氧革兰氏阳性菌,是目前利用整合生物加工技术生产纤维素乙醇的最重要的候选菌株之一.代谢物组可以反映细胞和环境因子相互作用,是系统生物学的重要组成部分.目前,尚无使用核磁共振(NMR)方法对热纤梭菌的代谢组进行研究的报道,而对热纤梭菌代谢物的归属是进行代谢组研究的基础.该文通过1H NMR和2D NMR技术,对热纤梭菌的中心代谢产物进行了归属.在归属过程中,发现了若干特殊的重要代谢产物,包括纤维糊精、磷酸烯醇式丙酮酸、赤藓糖-4-磷酸等.这些代谢物对热纤梭菌的胞内代谢具有特殊的意义.利用已归属的代谢物,对热纤梭菌的野生型和乙醇耐受菌株进行初步的代谢组分析表明,热纤梭菌乙醇耐受性的获得,可能与纤维二糖主动合成纤维糊精途径、非氧化磷酸戊糖途径的增强及糖酵解路径的抑制密切相关.

Clostridium thermocellum is a thermophilic anaerobic gram-positive bacteria that can efficiently utilize lignocelluloses. It is one of the most important candidate microorganisms for cellulosic ethanol production with consolidated bioprocessing. Metabolome reflects the interaction between cell and its environmental factors, and is an important component of system biology. In this work, 1H NMR and 2D NMR techniques were used to analysis the central metabolites of C. thermocellum. Some biologically significant metabolites were identified in the intracellular compartment of C. thermocellum, including such as cellodextrin, phosphoenolpyruvate and d-erythrose-4-phosphate. Preliminary multivariate statistical analysis of the wild type strain and ethanol tolerant strain showed various metabolic differences in several metabolic pathways including actively conversion of cellubiose to cellodextrin, enhancement of non-oxidative pentose phosphate pathway and suppression of Embden-Meyerhof-Parnas pathway.