Transcriptional response of Escherichia coli to ammonia and glucose fluctuations.

In large-scale production processes, metabolic control is typically achieved by limited supply of essential nutrients such as glucose or ammonia. With increasing bioreactor dimensions, microbial producers such as Escherichia coli are exposed to changing substrate availabilities due to limited mixing. In turn, cells sense and respond to these dynamic conditions leading to frequent activation of their regulatory programmes.

Switching between nitrogen and glucose limitation: Unraveling transcriptional dynamics in Escherichia coli.

Transcriptional control under nitrogen and carbon-limitation conditions have been well analyzed for Escherichia coli. However, the transcriptional dynamics that underlie the shift in regulatory programs from nitrogen to carbon limitation is not well studied. In the present study, cells were cultivated at steady state under nitrogen (ammonia)-limited conditions then shifted to carbon (glucose) limitation to monitor changes in transcriptional dynamics.

Engineering E. coli for large-scale production - Strategies considering ATP expenses and transcriptional responses.

Microbial producers such as Escherichia coli are evolutionarily trained to adapt to changing substrate availabilities. Being exposed to large-scale production conditions, their complex, multilayered regulatory programs are frequently activated because they face changing substrate supply due to limited mixing. Here, we show that E.

Slippery substrates impair function of a bacterial protease ATPase by unbalancing translocation versus exit.

Background: ATP-dependent proteases translocate and unfold their substrates.

Results: A human virus sequence with only Gly and Ala residues causes similar dysfunctions of eukaryotic and prokaryotic protease motors: unfolding failure.

Conclusion: Sequences with amino acids of simple shape and small size impair unfolding of contiguous stable domains.