title: Antimicrobial properties and death-inducing mechanisms of saccharomycin, a biocide secreted by Saccharomyces cerevisiae.
abstract: We recently found that Saccharomyces cerevisiae (strain CCMI 885) secretes antimicrobial peptides (AMPs) derived from the glycolytic enzyme glyceraldehyde 3-phosphate dehydrogenase (GAPDH) that are active against various wine-related yeast and bacteria. Here, we show that several other S. cerevisiae strains also secrete natural biocide fractions during alcoholic fermentation, although at different levels, which correlates with the antagonistic effect exerted against non-Saccharomyces yeasts. We, therefore, term this biocide saccharomycin. The native AMPs were purified by gel-filtration chromatography and its antimicrobial activity was compared to that exhibited by chemically synthesized analogues (AMP1 and AMP2/3). Results show that the antimicrobial activity of the native AMPs is significantly higher than that of the synthetic analogues (AMP1 and AMP2/3), but a conjugated action of the two synthetic peptides is observed. Moreover, while the natural AMPs are active at pH 3.5, the synthetic peptides are not, since they are anionic and cannot dissolve at this acidic pH. These findings suggest that the molecular structure of the native biocide probably involves the formation of aggregates of several peptides that render them soluble under acidic conditions. The death mechanisms induced by the AMPs were also evaluated by means of epifluorescence microscopy-based methods. Sensitive yeast cells treated with the synthetic AMPs show cell membrane disruption, apoptotic molecular markers, and internalization of the AMPs. In conclusion, our work shows that saccharomycin is a natural biocide secreted by S. cerevisiae whose activity depends on the conjugated action of GAPDH-derived peptides. This study also reveals that S. cerevisiae secretes GAPDH-derived peptides as a strategy to combat other microbial species during alcoholic fermentations.
authors: Unit of Bioenergy, Laboratório Nacional de Energia e Geologia, Estrada do Paço do Lumiar 22, 1649-038, Lisbon, Portugal.|Research Center Linking Landscape, Environment, Agriculture and Food (LEAF), Tapada da Ajuda, 1349-017, Lisbon, Portugal.
authors: Patrícia
authors: P
authors: Branco
authors: Unit of Bioenergy, Laboratório Nacional de Energia e Geologia, Estrada do Paço do Lumiar 22, 1649-038, Lisbon, Portugal.
authors: Diana
authors: D
authors: Francisco
authors: Unit of Bioenergy, Laboratório Nacional de Energia e Geologia, Estrada do Paço do Lumiar 22, 1649-038, Lisbon, Portugal.
authors: Margarida
authors: M
authors: Monteiro
authors: UCIBIO REquimte, Depart. Química, Faculdade de Ciências e Tecnologia (UNL), 2829-516, Monte Caparica, Portugal.|Centro de investigação interdisciplinar Egas Moniz ISCSEM, Quinta da Granja, 2829-511, Monte Caparica, Portugal.
authors: Maria Gabriela
authors: MG
authors: Almeida
authors: UCIBIO REquimte, Depart. Química, Faculdade de Ciências e Tecnologia (UNL), 2829-516, Monte Caparica, Portugal.|Centro de investigação interdisciplinar Egas Moniz ISCSEM, Quinta da Granja, 2829-511, Monte Caparica, Portugal.
authors: Jorge
authors: J
authors: Caldeira
authors: Department of Food Science, Faculty of Life Sciences, University of Copenhagen, Rolighedsvej 30, 1958, Frederiksberg C, Denmark.
authors: Nils
authors: N
authors: Arneborg
authors: Research Center Linking Landscape, Environment, Agriculture and Food (LEAF), Tapada da Ajuda, 1349-017, Lisbon, Portugal.
authors: Catarina
authors: C
authors: Prista
authors: Unit of Bioenergy, Laboratório Nacional de Energia e Geologia, Estrada do Paço do Lumiar 22, 1649-038, Lisbon, Portugal. helena.albergaria@lneg.pt.
authors: Helena
authors: http://orcid.org/0000-0002-9062-9827
authors: H
authors: Albergaria
mesh_terms: D017209:Apoptosis; D002462:Cell Membrane / Q000187:drug effects; D002850:Chromatography, Gel; D004202:Disinfectants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D004705:Endocytosis; D006863:Hydrogen-Ion Concentration; D050296:Microbial Viability / Q000187:drug effects*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D012995:Solubility
chemical_list: D004202:Disinfectants
keywords: Antimicrobial peptides; Apoptosis/necrosis; Cell-penetrating peptides; Glyceraldehyde 3-phosphate dehydrogenase; Non-Saccharomyces yeasts; Wine fermentation