Global spatial organization of ? proteobacterial nucleoids is determined by specific long-range interactions.

GCC was used to determine the response of P. aeruginosa nucleoid structure to different environmental conditions. Overall design: Pseudomonas aeruginosa strains were stored (-80°C) and cultured (37°C) on/in mineral salts medium (MM) with either 0.05% (w/v) or 0.2% (w/v) NH4Cl. NH4Cl was used as nitrogen source. The cells were cultivated with 2% (w/v) sodium gluconate. For GCC analyses, P. aeruginosa strains were recovered from -80°C on LB-plates for 24 hours prior to starter culture inoculation. Starter cultures were cultured (37°C, 160rpm, O/N) in MM medium (gluconate 2% w/v) with or without nitrogen, as indicated. Test cultures were inoculated, from the starter cultures, in MM media gluconate (2% w/v) with or without nitrogen, grown (37°C, 160rpm) and harvested at an OD600 = 0.6-8 (log phase) or OD600 = 4-5 (stationary phase).