Circular treemaps visualizing differentially expressed functional protein categories. Proteins detected by mass spectrometry were clustered according to their pathway annotation in COG covering two levels of specificity (Tatusov et al. ). The size of a sector is proportional to the number of proteins found in one specific pathway in relation to the total protein number. The color code represents the log2 mean fold change (log2 FC) of protein quantity in one pathway. The color blue codes for an underrepresentation, red for an overrepresentation of the proteins in a pathway compared to the reference population (RP, μ = 0.2 h−1). Pathways with a fold change in the range log2 FC < −0.58 and log2 FC > 0.58 are labeled with the respective pathway name. Pathways that were significantly changed using GAGE (Luo et al. ) and Globaltest (Goeman et al. ) gene set analysis are additionally marked (*). a. Comparison of the subpopulations C1/C2 and C2/Cx at growth rates 0.1 h−1 and 0.7 h−1, respectively. b. Comparison of the subpopulations C1 and C2 at μ = 0.1 h−1 with RP. c. Comparison of the subpopulations C2 and Cx at μ = 0.7 h−1 with RP.