FIG 2.

Physical complementation of nanI null mutant strain BMC202. (A) Physical complementation protocol. The BMC2072 or BMC207 strain was cultured in TH medium at 37°C for 2 h, and the supernatants were then collected. Washed BMC202 cells (100 μl) were inoculated into 1-ml portions of these supernatants and anaerobically cultured in GasPak jars for 2 h or 4 h. The supernatants were then collected to detect sialidase activities and for ETX Western blotting. O/N, overnight culture. (B) Sialidase activities were measured in the supernatants from 2-h TH culture supernatants of strain BMC2072 or BMC207 and in the same supernatants that were inoculated with washed BMC202 cells [BMC2072(202) or BMC207(202), respectively] and then cultured for 2 h or 4 h. All experiments were repeated three times, and mean values are shown. The error bars indicate standard deviations. (C) A representative Western blot (from three independent experiments) for ETX production by washed BMC202 cells cultured in BMC2072 supernatant versus BMC207 supernatant for 2 h or 4 h.