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Pichia anomala DBVPG 3003 secretes a ubiquitin-like protein that has antimicrobial activity

Jessica De Ingeniis1, Nadia Raffaelli, Maurizio Ciani

  • 1Istituto di Biotecnologie Biochimiche, Università Politecnica delle Marche, Via Ranieri, 60131 Ancona, Italy.

Applied and Environmental Microbiology
|December 31, 2008
PubMed

Insights

Pichia anomala DBVPG 3003 secretes a novel antifungal peptide, Pikt, similar to ubiquitin. This Pikt peptide exhibits killer activity against Brettanomyces/Dekkera yeasts by interacting with their cell walls.

Area of Science:

  • Microbiology
  • Mycology
  • Biochemistry

Background:

  • Brettanomyces/Dekkera yeasts are spoilage organisms in winemaking.
  • Pichia anomala produces a killer toxin (Pikt) with antifungal properties.
  • Understanding Pikt's mechanism is crucial for controlling yeast spoilage.

Purpose of the Study:

  • To characterize the Pichia anomala killer toxin (Pikt).
  • To investigate the molecular properties and activity of Pikt.
  • To determine if Pikt is related to known yeast toxins or peptides.

Main Methods:

  • Purification of Pikt from Pichia anomala culture supernatant.
  • Analysis of Pikt's interaction with yeast cell walls (beta-1,6-glucan).
  • Comparison of Pikt's molecular mass, N-terminal sequences, and antibody recognition with ubiquitin.

Main Results:

  • Pikt has antifungal activity against Brettanomyces/Dekkera yeasts.
  • Pikt binds to beta-1,6-glucan in the cell wall of sensitive yeasts.
  • Purified Pikt is an 8 kDa protein, similar to ubiquitin in mass and sequence, but sensitive to proteases.

Conclusions:

  • Pikt is a novel ubiquitin-like peptide with killer activity.
  • Pikt's antifungal mechanism differs from Saccharomyces cerevisiae toxin K1.
  • Pikt represents a new class of antifungal agents potentially useful in controlling spoilage yeasts.

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