cell membrane through a protein which binds to both DNA and membrane or through nascent transcription and the translation of membrane-anchored proteins. (iv) Transcription activity can generate supercoiling-diffusion barriers. An actively transcribing RNAP has been shown to block dissipation of plectonemic supercoils, thereby forming a supercoiling-diffusion barrier. Growth-phase dependent nucleoid dynamics The nucleoid reorganizes in stationary phase cells suggesting that the nucleoid structure is highly dynamic, determined by the physiological state of cells. A comparison of high-resolution contact maps of the nucleoid revealed that the long-range contacts in the Ter macrodomain increased in the stationary phase, compared to the growth phase. Furthermore, CID boundaries in the stationary phase were different from those found in the growth phase. Finally, nucleoid morphology undergoes massive transformation during prolonged stationary phase; the nucleoid exhibits ordered, toroidal structures. Growth-phase specific changes in nucleoid structure could be brought about by a change in levels of nucleoid-associated DNA architectural proteins (the NAPs and the Muk subunits), supercoiling, and transcription activity. The abundance of NAPs and the Muk subunits changes according to the bacterial growth cycle. Fis and the starvation-induced DNA binding protein Dps, another NAP, are almost exclusively present in the growth phase and stationary phase respectively. Fis levels rise upon entry into exponential phase and then rapidly decline while cells are still in the exponential phase, reaching levels that are undetectable in stationary phase. While Fis levels start to decline, levels of Dps start to rise and reach a maximum in the stationary phase. A dramatic transition in the nucleoid structure observed in the prolonged stationary phase has been mainly attributed to Dps. It forms DNA/crystalline assemblies that act to protect the nucleoid from DNA damaging agents present during starvation. HU, IHF, and H-NS are present in both growth phase and stationary phase. However, their abundance changes significantly such that HU and Fis are the most abundant NAPs in the growth phase, whereas IHF and Dps become the most abundant NAPs in the stationary phase. HUαα is the predominant form in early exponential phase, whereas the heterodimeric form predominates in the stationary phase, with minor amounts of homodimers. This transition has functional consequences regarding nucleoid structure, because the two forms appear to organize and condense DNA differently; both homo- and heterodimers form filaments, but only the homodimer can bring multiple DNA segments together to form a DNA network. The copy number of MukB increases two-fold in