TABLE 2.

Characterization of genes that affect NTD production

StrainTn10 inserted geneFunction or similarityNTD titer (μg/ml)a
61884NAbNA<5
84R5NANA200
84R5-UP1glcPGlucose/mannose:H+ symporter700
84R5-DN1ymfISimilar to 3-oxoacyl-acyl carrier protein reductase<5
84R5-DN2ccpACatabolite control protein A5
  • a B. subtilis strains were grown overnight on L agar plates at 30°C, after which they were inoculated into S7N medium containing excess (1%) glucose and incubated for 24 h at 37°C. NTD titers were determined by using paper disk agar diffusion assays with B. subtilis TI130R5 (rpoB5 ntdA::Tn10 amyE::PntdABC-lacZ) as the indicator strain (see Materials and Methods). NTD titers for strains 84R5 and 84R5-UP1 were determined after appropriate dilution of their cultured broth. Purified NTD (>95% purity) was used as the standard. At least two independent experiments were performed.

  • b NA, not applicable.