FIG. 2.

YBT production in King's medium B by the E. coli strains ECOR 69, ECOR 10, and ECOR 4 received from different origins: (P), received from B. Picard; (D), received from E. Denamur; and (J), received from J. R. Johnson (Table 2). The strains were grown at 37°C for 2 days in either one still petri dish with one agar block (black bars) or one shaken Erlenmeyer flask (white bars). YBT production was assessed by the Fe-YBT HPLC peak area at 403 nm.