Dataset Information

Metabolic adaption of ethanol-tolerant Clostridium thermocellum.

ABSTRACT: Clostridium thermocellum is a major candidate for bioethanol production via consolidated bioprocessing. However, the low ethanol tolerance of the organism dramatically impedes its usage in industry. To explore the mechanism of ethanol tolerance in this microorganism, systematic metabolomics was adopted to analyse the metabolic phenotypes of a C. thermocellum wild-type (WT) strain and an ethanol-tolerant strain cultivated without (ET0) or with (ET3) 3% (v/v) exogenous ethanol. Metabolomics analysis elucidated that the levels of numerous metabolites in different pathways were changed for the metabolic adaption of ethanol-tolerant C. thermocellum. The most interesting phenomenon was that cellodextrin was significantly more accumulated in the ethanol-tolerant strain compared with the WT strain, although cellobiose was completely consumed in both the ethanol-tolerant and wild-type strains. These results suggest that the cellodextrin synthesis was active, which might be a potential mechanism for stress resistance. Moreover, the overflow of many intermediate metabolites, which indicates the metabolic imbalance, in the ET0 cultivation was more significant than in the WT and ET3 cultivations. This indicates that the metabolic balance of the ethanol-tolerant strain was adapted better to the condition of ethanol stress. This study provides additional insight into the mechanism of ethanol tolerance and is valuable for further metabolic engineering aimed at higher bioethanol production.

SUBMITTER: Zhu X

PROVIDER: S-EPMC3728321 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Metabolic adaption of ethanol-tolerant Clostridium thermocellum.

Zhu Xinshu X Cui Jiatao J Feng Yingang Y Fa Yun Y Zhang Jingtao J Cui Qiu Q

PloS one 20130730 7

Clostridium thermocellum is a major candidate for bioethanol production via consolidated bioprocessing. However, the low ethanol tolerance of the organism dramatically impedes its usage in industry. To explore the mechanism of ethanol tolerance in this microorganism, systematic metabolomics was adopted to analyse the metabolic phenotypes of a C. thermocellum wild-type (WT) strain and an ethanol-tolerant strain cultivated without (ET0) or with (ET3) 3% (v/v) exogenous ethanol. Metabolomics analys ...[more]

PMID: 23936233

Similar Datasets

Project description:Clostridium thermocellum is a Gram-positive, anaerobic, thermophilic bacterium that ferments cellulose into ethanol. It is a candidate industrial consolidated bioprocess (CBP) biocatalyst for lignocellulosic bioethanol production. However, C. thermocellum is relatively sensitive to ethanol compared to yeast. Previous studies have investigated the membrane and protein composition of wild-type and ethanol tolerant strains, but relatively little is known about the genome changes associated with the ethanol tolerant C. thermocellum strain. In this study, C. thermocellum cultures were grown to mid-exponential phase and then either shocked with the supplementation of ethanol to a final concentration of 3.95 g/L (equal to 0.5% [v/v]) or were untreated. Samples were taken pre-shock and 2, 12, 30, 60, 120, 240 min post-shock for multiple systems biology analyses. The addition of ethanol dramatically reduced the C. thermocellum growth and the final cell density was approximately half of the control fermentations, with concomitant reductions in substrate consumption in the treated cultures. The response of C. thermocellum to ethanol was dynamic and involved more than six hundred genes that were significantly and differentially expressed between the different conditions over time and every functional category was represented. Cellobiose was accumulated within the ethanol-shocked C. thermocellum cells, as well as the sugar phosphates such as fructose-6-P and cellobiose-6-P. The comparison and correlation among intracellular metabolites, proteomic and transcriptomics profiles as well as the ethanol effects on cellulosome, hydrogenase glycolysis and nitrogen metabolism are discussed, which led us to propose that C. thermocellum may utilize the nitrogen metabolism to bypass the arrested carbon metabolism in responding to ethanol stress shock, and the nitrogen metabolic pathway and redox balance may be the key target for improving ethanol tolerance and production in C. thermocellum.

Dataset Information

Metabolic adaption of ethanol-tolerant Clostridium thermocellum.

Publications

Metabolic adaption of ethanol-tolerant Clostridium thermocellum.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure