Isolation and Characterization of New Metschnikowia pulcherrima Strains as Producers of the Antimicrobial Pigment Pulcherrimin

Abstract

Metschnikowia pulcherrima is a highly effective biocontrol yeast due to its pigment pulcherrimin that accumulates in the cells and in the growth medium. Three different strains of M. pulcherrima were isolated from local grapes. The yeast isolates were characterized on the basis of their biochemical, physiological and ITS1-5.8 s rDNA-ITS2 region. Based on the obtained results, the M. pulcherrima isolates were identifi ed as new strains of M. pulcherrima. Strong antagonistic activities of the M. pulcherrima strains on the human pathogens Proteus vulgaris, Escherichia coli, Candida albicans, Candida parapsilosis, Candida krusei, and Trichosporon mucoides were determined. In addition, antagonistic effects of these M. pulcherrima strains were also tested against Aspergillus fl avus, Aspergillus fumigatus, Aspergillus niger, Trichoderma spp., Paecilomyces spp., and Bipolaris spp. and it was shown that the three different strains of M. pulcherrima also have an antagonistic effect on the growth of these fungal species at different extents. This study showed that all three strains of M. pulcherrima produce the same amount of the pigment pulcherrimin, but their antimicrobial activities on different microorganisms show important variations.

Biocontrol Activity of the Local Strain of Metschnikowia pulcherrima on Different Postharvest Pathogens

“…Isolation and characterization of M. pulcherrima UMY15 strain were described previously [16]. M. pulcherrima UMY15 strain was cultivated in YPD medium (1% yeast extract, 2% peptone, and 2% glucose) for antagonistic activity tests.…”

“…Antagonistic effects of different M. pulcherrima strains on different species of Candida , Aspergillus , E. coli , Proteus vulgaris , Trichosporon mucoides , and on Trichoderma spp., were also reported [16]. M. pulcherrima produces a secondary metabolite pulcherrimin and secretes it to the growth medium [17].…”

“…Pulcherrimin forms a chelate complex and immobilizes the iron ions in the growth medium [15, 18]. Hence, it seems that M. pulcherrima strains exert their antagonistic effects on the other microorganisms by the depletion of iron in the growth medium [15, 16, 18]. In addition to the pulcherrimin pigment, there is evidence indicating that M. pulcherrima also secretes lytic enzymes such as chitinase that contribute to the overall antagonistic effects of related M. pulcherrima strains [19].…”

Wine microbiome: A dynamic world of microbial interactions

“…These strains expressed a broad and effective antimicrobial action against undesired wild spoilage yeasts, including those of the Brettanomyces/Dekkera, Hanseniaspora and Pichia genera (Oro et al, 2014). The antimicrobial activity of Metschnikowia pulcherrima seems to come from the pulcherriminic acid (the precursor of pulcherrimin pigment), which depletes the medium of iron, making it unavailable to the other yeasts (Sipiczki, 2006;Türkel & Ener, 2009;Oro et al, 2014).…”

Antimicrobial Activity of Pulcherrimin Pigment Produced by Metschnikowia Pulcherrima Against Various Yeast Species

“…Hence, the strains of M. pulcherrima that produce high amounts of pulcherrimin are of great interest for the inhibition of the growth of pathogenic bacteria, yeasts, and molds. The pigment pulcherrimin produced by different strains of M. pulcherrima can be a good alternative for topical applications in the prevention against certain bacterial, yeast and fungal infections in humans (Türkel and Ener, 2009). The aim of this study was to confirm the antimicrobial activity of pulcherrimin pigment produced by Metschnikowia pulcherrima against various yeast species.…”