Production of acidocin B, a bacteriocin of Lactobacillus acidophilus M46 is a plasmid-encoded trait: Plasmid curing, genetic marking by in vivo plasmid integration, and gene transfer |
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| Authors: | Jos M.B.M. van der Vossen Marcel H.M. van Herwijnen Rob J. Leer Bart ten Brink Peter H. Pouwels Jos H.J. Huis in `t Veld |
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| Affiliation: | TNO Nutrition and Food Research, Department of Microbiologoy, P.O. Box 360, 3700 AJ Zeist, the Netherlands; TNO Health Research, Molecular Genetics and Gene Technology, Medical Biological Laboratory, P.O. Box 5815, 2280 HV Rijswijk, the Netherlands |
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| Abstract: | Abstract Plasmid-curing studies suggest that acidocin B production is encoded by the 14-kb plasmid pCV461 in Lactobacillus acidophilus M46. Loss of pCV461 from the original producer strain M46 did not coincide with loss of immunity to acidocin B. Bacteriocin activity determination after SDS-PAGE showed that a substance of 2.4 kDa, absent in the culture supernatant of the mutant strain M46A2, lacking pCV461, represented acidocin B activity. In order to introduce a positive selection criterion, pCV461 was marked in vivo by the erythromycin resistance marker of pE194, present on pUC19 containing a 1.4-kb Hin dIII fragment of pCV461, after plasmid integration. Introduction of this recombinant plasmid into the mutant strain M46A2 or Lactobacillus plantarum resulted in erythromycin-resistant, acidocin B-producing transformants, showing unambiguously that acidocin B is encoded by pCV461. |
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| Keywords: | Lactobacillus acidophilus Bacteriocin Plasmid curing Campbell-like integration Gene transfer |
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