We published a paper "Metabolic Adaption of Ethanol-Tolerant Clostridium thermocellum" on PLoS ONE.

[2013.7.31] Our metabolomics research about the ethanol tolerance of Clostridium thermocellum is published on PloS ONE on 30th July. 

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.

The Ph.D student Xinshu Zhu is the first author. Professor Qiu Cui and the assitant professor Jingtao Zhang are the corresponding authors. The work was supported by the National Basic Research Program of China (973 Program), the Instrument Developing Project of the Chinese Academy of Sciences, and the Key Technologies R&D Program from Ministry of Science and Technology of China.

NCBI PubMed 

Xinshu Zhu, Jiatao Cui, Yingang Feng, Yun Fa, Jingtao Zhang*, Qiu Cui* (2013) Metabolic Adaption of Ethanol-Tolerant Clostridium thermocellum. PLoS ONE 8(7), e70631. [Full text (Publisher website)]