FIG 7.

(A) Specificity analysis of the subtilomycin immunity gene apnI by sensitive test in CU1065. Gradient amounts of antibiotics were added from the arrow and moving clockwise. Vancomycin concentrations were 0.3375 nM, 0.675 nM, 1.35 nM, 2.7 nM, 5.4 nM, and 10.8 nM; nisin concentrations were 0.41 μM, 0.82 μM, 1.64 μM, 3.28 μM, 6.54 μM, and 13.08 μM. (B) Detection of cross-resistance to paenibacillin and subtilomycin in CU1065 conferred by genes apnI and paeI, respectively. The amounts of crude paenibacillin were applied with diluted series 2 times and not quantified. Gradient amounts of subtilomycin were added from the arrow and moving clockwise: 0.5 μM, 1 μM, 2 μM, 4 μM, 8 μM, and 16 μM. Each assay was independently repeated at least three times.