title: Influence of nitrogen supply on the production of higher alcohols/esters and expression of flavour-related genes in cachaça fermentation.
abstract: This study provides the first attempt to analyse the influence of ammonium supplements on sugar-cane juice fermentation and the flavour profile in a cachaça industrial process. The objective was to find a relationship between higher alcohol/ester content and the transcription levels of the main genes involved in production of these compounds under cachaça fermentation. Sugar-cane juice with a low amount of assimilable nitrogen (81 mg N/L), was further supplemented with mid-range or high concentrations of ammonium sulfate. Overall, higher alcohol production was reduced by ammonium supplementation, and this can be correlated with a general downregulation of genes encoding decarboxylases and dehydrogenases of the Ehrlich pathway. The production of acetate esters was enhanced by mid-range ammonium supplementation and the production of acyl esters by high ammonium supplementation. The acyl esters could be correlated with expression of alcohol acyl-transferase EEB1 and the acyl esterase IAH1.
authors.affiliation: Interdepartmental Research Group in Metabolic Engineering, Federal University of Pernambuco, Av. Moraes Rego 1235, 50670-901 Recife, Pernambuco, Brazil. esteban.espinosa.vidal@gmail.com
authors.forename: Esteban Espinosa
authors.initials: EE
authors.lastname: Vidal
authors.forename: Gustavo M
authors.initials: GM
authors.lastname: de Billerbeck
authors.forename: Diogo Ardaillon
authors.initials: DA
authors.lastname: Simões
authors.forename: Alexandre
authors.initials: A
authors.lastname: Schuler
authors.forename: Jean Marie
authors.initials: JM
authors.lastname: François
authors.forename: Marcos Antonio
authors.initials: MA
authors.lastname: de Morais
mesh_terms: D000434:Alcoholic Beverages / Q000032:analysis / Q000382:microbiology*; D003470:Culture Media / Q000378:metabolism; D004952:Esters / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D015966:Gene Expression Regulation, Fungal; D009584:Nitrogen / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism*; D031786:Saccharum / Q000737:chemistry / Q000382:microbiology*
chemical_list: D003470:Culture Media; D004952:Esters; D029701:Saccharomyces cerevisiae Proteins; D000431:Ethanol; D009584:Nitrogen