title: Production, purification, and characterization of a novel killer toxin from Kluyveromyces siamensis against a pathogenic yeast in crab.
abstract: The yeast Kluyveromyces siamensis HN12-1 isolated from mangrove ecosystem was found to be able to produce killer toxin against the pathogenic yeast (Metschnikowia bicuspidata WCY) in crab. When the killer yeast was grown in the medium with pH 4.0 and 0.5% NaCl and at 25 °C, it could produce the highest amount of killer toxin against the pathogenic yeast M. bicuspidata WCY. The killing activity of the purified killer toxin against the pathogenic yeast M. bicuspidata WCY was the highest when it was incubated at 25 °C in the assay medium without added NaCl and pH 4.0. The molecular weight of the purified killer toxin was 66.4 kDa. The killer toxin produced by the yeast strain HN12-1 could kill only the whole cells of M. bicuspidata WCY among all the yeast species tested in this study. This is the first time to report that the killer toxin produced by the yeast K. siamensis HN12-1 isolated from the mangrove ecosystem only killed pathogenic yeast M. bicuspidata WCY.
authors.affiliation: UNESCO Chinese Centre of Marine Biotechnology, Ocean University of China, Yushan Road, No. 5, Qingdao, China.
authors.forename: Muhammad Aslam
authors.initials: MA
authors.lastname: Buzdar
authors.forename: Zhe
authors.initials: Z
authors.lastname: Chi
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.forename: Ming-Xia
authors.initials: MX
authors.lastname: Hua
authors.forename: Zhen-Ming
authors.initials: ZM
authors.lastname: Chi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000935:Antifungal Agents / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D003386:Brachyura / Q000382:microbiology*; D055646:Killer Factors, Yeast / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D007716:Kluyveromyces / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D015003:Yeasts / Q000187:drug effects*
chemical_list: D000935:Antifungal Agents; D055646:Killer Factors, Yeast