title: Fermentability of grape must after inhibition with dimethyl dicarbonate (DMDC).
abstract: Dimethyl dicarbonate (DMDC) was added to grape must and to synthetic media and results showed that, at 20 degrees C, 150 mg.L(-)(1) DMDC completely inhibited the fermentation of a grape must that was previously inoculated with 10(6) cells.mL(-)(1) Saccharomyces bayanus and Saccharomyces uvarum. Brettanomyces intermedius, Candida guilliermondii, Hansenula jadinii, Hansenula petersonii, Kloeckera apiculata, Pichia membranaefaciens, and Saccharomyces cerevisiae were inhibited by 250 mg.L(-)(1). Candida valida was inhibited in the presence of 350 mg.L(-)(1), whereas Hanseniaspora osmophila, Saccharomycodes ludwigii, Schizosaccharomyces pombe, and Zygosaccharomyces bailii required 400 mg.L(-)(1). Delay of fermentation (but not inhibition) was noted in the presence of 400 mg.L(-)(1) for the following cultures: Brettanomyces anomalus, Hanseniaspora uvarum, Metschnikowia pulcherrima, Schizosaccharomyces japonicus, Torulaspora delbrueckii, and Zygosaccharomyces florentinus. Acetobacter aceti and Lactobacillus sp. were completely inhibited using 1000 and 500 mg.L(-)(1) DMDC, respectively. The fermentation of a grape must inoculated with 10(6) cells.mL(-)(1) of different wine yeasts was delayed for 4 days after the prior addition of 200 mg.L(-)(1) of DMDC; 200 mg.L(-)(1) DMDC did not show any residual inhibitory effect after 12 h, nor did 300 mg.L(-)(1) 24 h after the addition. In cellar experiments, indigenously contaminated grape musts (with and without skins) showed a delay in fermentation of 48 h after the addition of only 50 mg.L(-)(1) DMDC. The possibility of using DMDC (as pure grade as commercially available) in grape must as a disinfectant for the decontamination of musts indigenously contaminated with wild yeast should be considered seriously, despite its apparent low solubility in water.
authors.affiliation: Istituto Sperimentale per l'Enologia, Sezione di Microbiologia, via P. Micca 35, 14100 Asti, Italy. sezione.microbiologia@tin.it
authors.forename: Claudio
authors.initials: C
authors.lastname: Delfini
authors.forename: Piero
authors.initials: P
authors.lastname: Gaia
authors.forename: Raffaella
authors.initials: R
authors.lastname: Schellino
authors.forename: Morela
authors.initials: M
authors.lastname: Strano
authors.forename: Adolfo
authors.initials: A
authors.lastname: Pagliara
authors.forename: Stefano
authors.initials: S
authors.lastname: Ambrò
mesh_terms: D000091:Acetobacter / Q000378:metabolism; D002175:Candida / Q000378:metabolism; D004047:Diethyl Pyrocarbonate / Q000031:analogs & derivatives* / Q000494:pharmacology*; D005285:Fermentation; D005511:Food Handling; D007778:Lactobacillus / Q000378:metabolism; D010843:Pichia / Q000378:metabolism; D012440:Saccharomyces / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D027843:Vitis / Q000378:metabolism* / Q000382:microbiology*; D014920:Wine / Q000382:microbiology*; D015003:Yeasts / Q000378:metabolism
chemical_list: C061815:dimethyl pyrocarbonate; D004047:Diethyl Pyrocarbonate