Fig. 1. Deletion of bamD leads to cell death during stationary phase and a highly permeable membrane.

a bamD deletion leads to slower growth in log phase and a decrease in OD₆₀₀ in stationary phase compared with the parent strain bamA^E470K. Left: OD₆₀₀ measurements starting from a diluted overnight culture. N = 3 biological replicates. Curves are mean values, and shaded regions represent 1 standard deviation. Right: corresponding growth rates as quantified by d ln(OD)/dt. b ΔbamD and mlaA* cells exhibited similar decreases in OD when transferred from log phase to the spent medium of wild-type E. coli MC4100 cells, while the parent strain maintained a stable OD. All OD measurements were normalized to the value upon transfer to spent medium at t = 0. N = 3 biological replicates. Curves are mean values, and shading represents 1 standard deviation. c ΔbamD cells exhibited inhibited growth on plates with bacitracin or SDS-EDTA compared with LB plates, whereas growth of the parent strain was not affected by either treatment. Data are representative of three biological replicates. d ΔbamD cells exhibited increased OM permeability compared with the parent strain as measured by the intake of fluorescent 1-N-phenyl-naphthylamine (NPN), normalized by OD₆₀₀. Data are presented as mean values ± 1 standard deviation. N = 3 biological replicates.