K-means clustering of the complete data set (K = 18). Each box shows a transcriptional response of genes partitioned into a separate cluster. A cluster number is shown in the bottom right corner of each box. The total number of genes in each cluster is shown in the top left corner of each cluster. The 15 pairwise comparisons obtained among six different growth conditions are indicated on the x axis; comparisons are listed in the bottom right corner. The SLRs of expression are indicated on the y axis. The lines in each cluster represent the data for individual genes. Lines are colored as follows, according to the response of the genes in each cluster to osmotic and/or heat stresses, and/or to the presence of GB in the medium: yellow, genes responding to heat stress only; green, osmotic stress only; blue, osmotic and heat stresses; purple, presence of GB; teal, osmotic and heat stresses and presence of GB; black, no difference. The designation of each cluster is also shown in Table 2. The red/pink line in each cluster designates the centroid. Comparisons represent growth condition differences as follows (from left to right): 1, salt concentration; 2, salt and GB; 3, temperature; 4, salt and temperature; 5, salt, temperature, and GB; 6, presence of GB; 7, salt, temperature, and GB; 8, temperature and GB; 9, temperature; 10, salt and temperature; 11, temperature; 12, temperature and GB; 13, salt; 14, salt and GB; 15, presence of GB.

Responses of genes of the oxidative-stress regulon to osmotic and heat stresses. The Venn diagram indicates genes that showed at least twofold overexpression under a single stress or under a combination of both stresses. There were no genes that were up-regulated under both individual osmotic and heat stresses but not when both stresses were applied simultaneously.

Cell motility of E. coli NCM3722 at different temperatures and osmotic contents of the medium. A, 30°C, no NaCl; B, 30°C, 0.3 M NaCl; C, 30°C, 0.6 M NaCl; D, 41°C, no NaCl; E, 42°C, no NaCl; F, 43°C, no NaCl.