Extended Data Fig. 1: Screening of BfUbb sensitive B. fragilis strains.
a, Agar spot analysis is used to screen BfUbb-sensitive B. fragilis strains on a BfUbb-containing plate. 22 B. fragilis strains were spotted on a BHIS plate spread with 100 μg of BfUbb to evaluate their BfUbb sensitivity. The selected BfUbb-sensitive strains are listed on the right and underlined in red. b, Minimum inhibitory concentration (MIC) assays of BfUbb, tetracycline (tet), and chloramphenicol (cam) on B. fragilis GS077 and GS076. Strains were cultured in BHIS medium containing BfUbb, tet, or cam with the indicated gradient concentrations. Dotted lines represent the 50% concentrations of the control strains (CT). Data are expressed as the mean ± s.d. from three independent experiments. c, Western immunoblot analyses of BfUbb in the whole cell lysate (WCL) and culture supernatant (Sup) of strains of B. fragilis NCTC 9343 wildtype, ubb deleted mutant and ubb restored mutant. d, 5 µl culture supernatant of B. fragilis NCTC 9343 wildtype, ubb deleted mutant, and ubb restored mutant are spotted on the BHIS plates and then overlaid with a layer of agar containing the indicated strains. For a, c, and d, experiments were conducted at least three times with consistent results.
