title: A novel killer protein from Pichia kluyveri isolated from an Algerian soil: purification and characterization of its in vitro activity against food and beverage spoilage yeasts.
abstract: A novel killer protein (Pkkp) secreted by a Pichia kluyveri strain isolated from an Algerian soil was active against food and beverage spoilage yeasts of the genera Dekkera, Kluyveromyces, Pichia, Saccharomyces, Torulaspora, Wickerhamomyces and Zygosaccharomyces. After purification by gel filtration chromatography Pkkp revealed an apparent molecular mass of 54 kDa with SDS-PAGE. Minimum inhibitory concentrations (MICs) of purified Pkkp exhibited a high in vitro activity against Dekkera bruxellensis (MICs from 64,000- to 256,000-fold lower than that exhibited by potassium metabisulphite) and Saccharomyces cerevisiae (MICs from 32,000- to 64,000- fold lower than potassium sorbate). No in vitro synergistic interactions (calculated by FIC index - Σ FIC) were observed when Pkkp was used in combination with potassium metabisulphite, potassium sorbate, or ethanol. Pkkp exhibited a dose-response effect against D. bruxellensis and S. cerevisiae in a low-alcoholic drink and fruit juice, respectively. The results of the present study suggest that Pkkp could be proposed as a novel food-grade compound useful for the control of food and beverage spoilage yeasts.
authors.affiliation: Department of Molecular and Cellular Biology, Natural and Life Sciences Faculty, Abbes Laghrour University of Khenchela, Route Batna, 40004, Khenchela, Algeria, labkenza@yahoo.fr.
authors.forename: Fatima-Zohra Kenza
authors.initials: FZ
authors.lastname: Labbani
authors.forename: Benedetta
authors.initials: B
authors.lastname: Turchetti
authors.forename: Leila
authors.initials: L
authors.lastname: Bennamoun
authors.forename: Scheherazad
authors.initials: S
authors.lastname: Dakhmouche
authors.forename: Rita
authors.initials: R
authors.lastname: Roberti
authors.forename: Lanfranco
authors.initials: L
authors.lastname: Corazzi
authors.forename: Zahia
authors.initials: Z
authors.lastname: Meraihi
authors.forename: Pietro
authors.initials: P
authors.lastname: Buzzini
mesh_terms: D000462:Algeria; D004357:Drug Synergism; D005516:Food Microbiology; D005656:Fungal Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000633:toxicity*; D008826:Microbial Sensitivity Tests; D009183:Mycotoxins / Q000737:chemistry / Q000302:isolation & purification* / Q000633:toxicity*; D010843:Pichia / Q000737:chemistry* / Q000302:isolation & purification; D012988:Soil Microbiology; D015003:Yeasts / Q000187:drug effects*
chemical_list: D005656:Fungal Proteins; D009183:Mycotoxins