Adaptive laboratory evolution of a genome-reduced Escherichia coli.

Synthetic biology aims to design and construct bacterial genomes harboring the minimum number of genes required for self-replicable life. However, the genome-reduced bacteria often show impaired growth under laboratory conditions that cannot be understood based on the removed genes. The unexpected phenotypes highlight our limited understanding of bacterial genomes. Here, we deploy adaptive laboratory evolution (ALE) to re-optimize growth performance of a genome-reduced strain. The basis for suboptimal growth is the imbalanced metabolism that is rewired during ALE. The metabolic rewiring is globally orchestrated by mutations in rpoD altering promoter binding of RNA polymerase. Lastly, the evolved strain has no translational buffering capacity, enabling effective translation of abundant mRNAs. Multi-omic analysis of the evolved strain reveals transcriptome- and translatome-wide remodeling that orchestrate metabolism and growth. These results reveal that failure of prediction may not be associated with understanding individual genes, but rather from insufficient understanding of the strain's systems biology

Chemocauterization of Congenital Fistula from the Accessory Parotid Gland

Congenital sialo-cutaneous fistula arising from the accessory parotid gland is extremely rare. Although the fistula tract can be successfully excised after making a skin incision along the skin tension line around the fistula opening, a facial scar inevitably remains. We here report a case of sialo-cutaneous fistula that was treated with chemocauterization with trichloroacetic acid (TCA). TCA cauterization is an easy and effective option for the treatment of congenital fistula from an accessory parotid gland, especially from the aesthetic point of view

Metabolic engineering of a reduced-genome strain of Escherichia coli for L-threonine production

© 2009 Lee et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens