Methods Bacterial strains All bacteria and phage strains used in this study are listed in Table 3. The copy number of λ genome was checked by PCR following the method of Powell et al. [64]. Table 3 Bacterial strains used in this study. Strain Relevant Genotype a Source IN56 MC4100 (λ cI857 S) [46] IN57 MC4100 (λ cI857 S C51S ) unpublished strain IN61 MC4100 (λ cI857 S105

C51S ) [46] IN62 MC4100 (λ cI857 S105) [46] IN63 MC4100 (λ cI857 S105 C51S/S76C ) [46] IN64 MC4100 (λ cI857 S C51S/F94C ) [46] IN65 MC4100 (λ cI857 S105 C51S/F94C ) unpublished strain IN66 MC4100 (λ cI857 S S68C ) [46] IN67 MC4100 (λ cI857 S105 C51S/I13C ) [46] IN68 MC4100 (λ cI857 Cell Cycle inhibitor S105 C51S/L14C ) [46] IN69 PI3K inhibitor MC4100 (λ cI857 S C51S/L14C ) [46] IN70 MC4100 (λ cI857 S C51S/F78C ) unpublished strain IN71 MC4100 (λ cI857 S105 C51S/F78C ) unpublished strain IN160 MC4100 (λ cI857 S A52G Cam) unpublished strain SYP026 MC4100 (λ cI857 p R ‘-M2), with p R ‘ mutations [50] SYP027 MC4100 (λ cI857 p R ‘-M1), with p R ‘ mutations [50] SYP028 MC4100 (λ cI857 p R ‘-M5), with p R ‘ mutations [50] SYP043 MC4100 (λ cI857 p R ‘-M4), with p R ‘ mutations [50] a S denotes wild-type holin gene, when expressed would produce both the S105

holin and S107 antiholin proteins. S105 signifies the mutant holin gene with its first codon altered from ATG (Met) to TTG (Leu), thus only produces the S105 holin protein. Experimental instrumentation E. coli cells lysogenic for λ phage were induced and observed to lyse in a temperature-controlled perfusion chamber. The experimental apparatus consisted of a 250 mL side-arm (on bottom) medium bottle clamped to an elevated support with tubing leading to an inline heater (SH-27B, Warner Instruments, New Haven, CT) that was controlled by a dual channel heater controller

(TC-344B, Warner Instruments, New Haven, CT). The growth medium, flowing Clomifene at a rate of ~1 mL/min (driven by gravity) and heated by the inline heater to the desired temperature, was introduced to a 358 μL perfusion chamber (RC-21B, Warner Instruments, New Haven, CT) mounted on a heating platform (PM2, Warner Instruments, New Haven, CT) that was controlled by the same dual channel heater controller to maintain the desired temperature. The internal temperature of the perfusion chamber was independently monitored by a thermistor. Waste BMS202 concentration flowed out of the perfusion chamber, pooled in a reservoir, and was siphoned into a 2 L bottle by a vacuum source. Both the perfusion chamber and the heating platform were placed on the stage of an inverted microscope (TS100, Nikon) for observation at 400× magnification. One of the microscope’s ocular lenses was replaced with a 10X MiniVID™ microscope camera (LW Scientific, Norcross, GA) to record individual lysis events onto a laptop computer at the rate of 1 frame per second.