Comparative Analysis On the Cytoplasmic and Membrane Proteomes of Clostridium Acetobutylicum Revealed the Molecular Basis for Butanol Tolerance

The solventogenic bacterium Clostridium acetobutylicum is the most important species of Clostridium used in the fermentation industry. However, the intolerance to butanol hampers the efficient production of solvents. Butanol toxicity has been attributed to the effect on cellular proteins, but the molecular mechanism underpinning butanol tolerance remains unclear. Here we report a systemic comparative analysis on the cytoplasmic and membrance proteomes of the wild type strain DSM 1731 and its butanol-tolerant mutant Rh8. We established the most comprehensive reference cytoplasmic and membrane proteome map for C. acetobutylicum. Furthermore, we identified 102 differentially expressed cytoplasmic proteins and 73 membrane proteins. Hierarchical clustering analysis revealed that Rh8 cells have evolved a more stabilized membrane structure, a more economic energy metabolism, and a more sensitive regulation on protein expression, to cope with the butanol challenge. This study allows us to obtain a systemic understanding on the molecular basis of butanol tolerance in C. acetobutylicum.