TABLE 2.

Phenotype of S. thermophilus LMD-9 derivativesa

LMD-9 strainBacteriocin productionbImmunityc
Wild type++
ΔblpR St strain
ΔblpH St strain
Δ(blpR St-blpH St) strain
Δ(blpD St-blpX St) strain
Δ(blpD St-blpF St) strain
Δ(blpG St-blpX St) strain++
ΔblpB St strain+d +
Δ(blpA St-blpB St) strain+
  • a The phenotypes of the strains were tested by the spot-on-lawn method for bacteriocin detection. Small volumes (5 μl) of D9C-30-induced (400 ng/ml) cultures of producer strains (OD600 of 1) were spotted on a soft agar layer containing 108 CFU of the indicator strains.

  • b Producer strains, LMD-9-derivative strains; indicator strains, LMG18311 and CNRZ1066.

  • c Producer strain, LMD-9 wild type; indicator strains, LMD-9-derivative strains.

  • d The inhibition zones produced by the ΔblpB St strain are smaller than those produced by the LMD-9 wild-type strain (Fig. 3B).