Frequency of strains tolerant of H₂O₂, menadione and pyrogallol.

aSpecies: CAS, L. casei; PAR, L. paracasei; RHA, L. rhamnosus. Sources: B, beverages; D, dairy products; H, human sources; M, meat products; P, plant material; SD, sourdoughs; U, unknown; W, wine. bTotal number of isolates. cFrequencies (%) of tolerant strains, calculated using the two-way contingency table.