Characteristics of Bacteriocin and Mucin Production Phenotypes in Lactobacillus plantarum 27

Phenotypic changes after plasmid curing experiment suggested that the bacteriocin production phenotype ($Bac^{+}$) might be linked to a chromosomal DNA and the mucin production phenotype ($Muc^{+}$) might be linked to a 62.5 kilobase (kb) plasmid (pMUC62) in Lactobacillus plantarum 27 isolated from meat starter culture. The non-mucoid ($Muc^{-}$) variants were missing pMUC62 but they produced bacteriocin as the wild strain ($Bac^{+}$). There was no difference in antibiotic resistance and sugar fermentation patterns between the wild strain ($Bac^{+}$ $Muc^{+}$) and the nonmucoid ($Bac^{+}$ $Muc^{-}$) variants. Antimicrobial spectrum of bacteriocin produced by both wild strain and $Muc^{-}$ variant of Lb. plantarum 27 included strains of Pediococcus acidilactici (A, M, H), Pediococcus sp. isolated from meat, Lactobacillus sp. isolated from meat, Lb. plantarum NCDO 955 and Staphylococcus aureus 485. Neither of the tested Gram negative bacteria were inhibited by bacteriocin. Antimicrobial activity of crude bacteriocin was retained after autoclaving, DNase or catalase treatment and exposure from pHs 4 to 9 but was lost after treating with several proteolytic enzymes and exposure at pH 10.