(332e) Multi-Platform Genome Re-Sequencing of Evolved Strains of the Cellulolytic Actinobacterium Thermobifida Fusca

Currently, one of the hurdles hindering efficient production of cellulosic biofuel is the recalcitrant nature of cellulose to hydrolysis. Thermobifida fusca is a high G-C content, thermophilic, gram-positive soil actinobacterium with high cellulolytic activity. T. fusca was adaptively evolved on the cellobiose and on glucose/cellobiose which generated a stress-relief cycle for evolution and then two strains: a specialist phenotype muC and a generalist phenotype muS that both converged to a similar cell yield (1.5g/L) were gained respectively. Both strains appeared to adjust their growth phenotype by modulating cellulase activity and intracellular ATP levels. To characterize the mutations of the genome during the evolutions, the high-throughput Illumina and 454 sequencing technologies were used. By re-sequencing these two strains by Illumina and 454 sequencing, 18 mutations in T. fusca muC and 14 mutations in T. fusca muS were confirmed as well as 48 found to be errors in the reference genome sequence of wild-type T. fusca. The genome-scale constraint-based model of T. fusca was built and verified by experiment. To connect the mutations caused by adaptive evolution to the metabolic changes, the flux variability of mutant and wild-type were predicted by the model and compared with each other.