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Caseicin, a bacteriocin from Lactobacillus casei

E Müller1, F Radler

  • 1Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg-Universität, Mainz, Germany.

Folia Microbiologica
|January 1, 1993
PubMed

Insights

The intracellular bacteriocin, caseicin 80, from Lactobacillus casei inhibits fructose incorporation into cells. This protein, likely encoded chromosomally, affects DNA and protein biosynthesis.

Area of Science:

  • Microbiology
  • Bacteriocin Research
  • Lactobacillus casei

Background:

  • Bacteriocins are ribosomally synthesized antimicrobial peptides.
  • Lactobacillus casei produces various bioactive compounds, including bacteriocins.
  • Intracellular bacteriocins present unique challenges in purification and characterization.

Purpose of the Study:

  • To purify and characterize the intracellular bacteriocin caseicin 80 from Lactobacillus casei strain B80.
  • To investigate the effects of caseicin 80 on cellular biosynthesis pathways.

Main Methods:

  • Purification of caseicin 80 from cell extracts of Lactobacillus casei B80.
  • Determination of protein molecular mass using SDS-PAGE (implied).
  • Analysis of the impact of caseicin 80 on the incorporation of radiolabeled precursors (14C) for DNA, protein, and carbohydrate biosynthesis.

Main Results:

  • Caseicin 80 was purified as a thermolabile protein with an apparent molar mass of 42 kDa.
  • No plasmids were detected in the bacteriocinogenic strain, suggesting chromosomal encoding.
  • Caseicin 80 influenced DNA and protein biosynthesis, though likely not as a primary effect.
  • Caseicin 80 specifically inhibited the incorporation of fructose, but not glucose, into cellular material.

Conclusions:

  • Caseicin 80 is an intracellular bacteriocin produced by Lactobacillus casei B80, likely encoded on the chromosome.
  • The primary mechanism of action appears to involve the inhibition of fructose uptake or metabolism.
  • Further research is needed to elucidate the precise molecular targets and pathways affected by caseicin 80.

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