Improved growth of Clostridium thermocellum AG553 via medium supplementation with formate and strain evolution

Strain AG553 was successfully constructed to eliminate side product formation during fermentation increasing the ethanol yield. Though ethanol yields were higher, the growth rate of the organism was significantly impaired. In order to improve growth rate, the organism was evolved and formate was added to the growth media. Both strategies successfully improved growth rate, but the mechanisms for that improved growth rate were still not understood. In order to get a better understanding of the mechanisms for improved growth, a proteomics and transcriptomics study of three strains: wild type, the unevolved AG553, and a representative evolved strain AG601 was completed with and without the addition of formate in the growth media. Overall design: There were three strains, with and without formate in quadruplicates. 24 samples in total were analyzed