Project description:Escherichia coli BW25113 is the parent strain of the Keio collection comprising nearly 4,000 single-gene deletion mutants. We report the complete 4,631,469-bp genome sequence of this strain and the key variations from the type strain E. coli MG1655.
Project description:Pseudogenes in the Escherichia coli genome are assumed to be non-functional. In this study, Keio collection BW25113∆yqiG and YqiG-producing strain (BW25113/pCA24N-YqiG) were used to evaluate the importance of pseudogene yqiG in hydrogen metabolism. Our results show pseudogene protein YqiG was identified as an essential protein in the production of biohydrogen from glucose. The mutant yqiG decreased biohydrogen production from 37 µmol mg-1 protein to 6 µmol mg-1 protein compared to the wild-type strain, and glucose consumption was reduced by 80%. Through transcriptional analysis, we found that the yqiG mutation represses pflB transcription tenfold; pflB encodes pyruvate-formate lyase, one of the key enzymes in the anaerobic metabolism of E. coli. Moreover, production of YqiG stimulated glycolysis and increased biohydrogen productivity 1.5-fold compared to that of the wild-type strain. Thus, YqiG is important for the central glycolysis reaction and is able to influence hydrogen metabolism activity in E. coli.
Project description:The present study investigated the role(s) of RNase I (encoded by the rna gene) in Escherichia coli by comparative gene expression analysis of an rna mutant and the isogenic wild-type E. coli strain BW25113. The transcriptomic analysis aims to provide mechanistic insight into aberrant phenotypes observed in the RNase I-deficient mutant.
Project description:RpoS, an alternative sigma factor, is critical for stress response in Escherichia coli.RpoS also acts as a global regulator for stress control of gene expression, and actually dose so in log stage and stationary stage. To further understand the effect of environmental stresses on in ethanologenic strains, DNA microarrys was used to analyze the expression profiles of E. coli and its rpoS mutant strain. Overall design: BW25113（rpoS-）and BW25113 were selected at log stages and stationary stage of early development for RNA extraction and hybridization on Affymetrix microarrays. To that end, we hand-selected BW25113 and BW25113（rpoS-） according at different treatments: BW25113（rpoS-）at log stage (BW25113(rpoS-) log), BW25113 at log stage (BW25113 log),BW25113（rpoS-）atstationary stage ( BW25113(rpoS-) stationary), BW25113 at stationary stage ( BW25113 stationary)