earticle

영어

Synthetic biology aims to redesign biological systems with desirable properties to provide the foundation for the biosynthesis of metabolites and proteins of commercial interest. In an effort to supply only the necessary genes for full functionality, large blocks of nonessential genes have been deleted1,2. However, removal of nonessential genes resulted in decrease of the growth rate of the reduced-genome E. coli MS56 on M9 minimal medium. To achieve increased growth rate, the MS56 was subjected to adaptive laboratory evolution (ALE) on M9 medium for 62 days. The evolved E. coli strain eJY62 exhibited unique physiological behaviors compared to the parental MS56 strain, suggesting that the ALE resulted in significant metabolic and regulatory perturbations. To investigate the ability to overcome the reduction of growth rate, we identified changes in genome sequences of evolved strain eJY62 by whole-genome resequencing. 41 SNP and deletion of 21kb length were detected and evaluated the contributions to the decreased growth rate by measurement of reproducibility of ALE. We identified that several mutations responsible for the improved fitness and these results demonstrate that the E. coli can adapt to the genome reduction with several mutations. This comprehensive genetic information will provide the foundation for designing and rewriting an artificial genome. (This work was supported by (2011-0031957, 2011-0031962).