Figure 3.

TcpA and CT production in O395 and its crp derivative KSK377. Strains were grown in LB medium pH 6.5, at 30°C (lanes 2 and 3), pH 8.5, at 30°C (lanes 4 and 5), pH 6.5, at 37°C (lanes 6 and 7), and pH 8.5, at 37°C (lanes 8 and 9). For each strain, approximately 6 μg of total protein was subjected to SDS/PAGE and stained with Coomassie blue. CS2-1 (tcpA), lane 1; O395, even-numbered lanes; KSK377, odd-numbered lanes. TcpA is shown by the arrow. The amount of CT in each culture supernatant is expressed at the bottom as ng/mg of protein per ml.