title: Impact of available nitrogen and sugar concentration in musts on alcoholic fermentation and subsequent wine spoilage by Brettanomyces bruxellensis.
abstract: The level of yeast assimilable nitrogen (YAN) supplementation required for Saccharomyces cerevisiae to complete fermentation of high sugar musts in addition to the impact of non-metabolized nitrogen on post-alcoholic spoilage by Brettanomyces bruxellensis was studied. A 2 × 3 factorial design was employed using a synthetic grape juice medium with YAN (150 or 250 mg N/L) and equal proportions of glucose/fructose (230, 250, or 270 g/L) as variables. S. cerevisiae ECA5 (low nitrogen requirement) or Uvaferm 228 (high nitrogen requirement) were inoculated at 10(5) cfu/mL while B. bruxellensis E1 or B2 were added once alcoholic fermentation ceased. Regardless of YAN concentration, musts that contained 230 or 250 g/L glucose/fructose at either nitrogen level attained dryness (mean = 0.32 g/L fructose) while those containing 270 g/L generally did not (mean = 2.5 g/L fructose). Higher concentrations of YAN present in musts yielded wines with higher amounts of α-amino acids and ammonium but very little (≤ 6 mg N/L) was needed by B. bruxellensis to attain populations ≥ 10(7) cfu/mL. While adding nitrogen to high sugar musts does not necessarily ensure completion of alcoholic fermentation, residual YAN did not affect B. bruxellensis growth as much as ethanol concentration.
authors.affiliation: School of Food Science, Washington State University, Pullman, WA 99164-6376, USA.
authors.forename: Bradford C
authors.initials: BC
authors.lastname: Childs
authors.affiliation: J.R. Simplot Company, Boise, ID 83605, USA.
authors.forename: Jeffri C
authors.initials: JC
authors.lastname: Bohlscheid
authors.affiliation: School of Food Science, Washington State University, Pullman, WA 99164-6376, USA. Electronic address: edwardsc@wsu.edu.
authors.forename: Charles G
authors.initials: CG
authors.lastname: Edwards
mesh_terms: D055168:Brettanomyces / Q000254:growth & development*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005632:Fructose / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D027843:Vitis / Q000382:microbiology*; D014920:Wine / Q000382:microbiology*
chemical_list: D005632:Fructose; D000431:Ethanol; D005947:Glucose; D009584:Nitrogen
keywords: Brettanomyces bruxellensis; Fermentation; Nitrogen; Saccharomyces cerevisiae; Sugar