title: A novel β-glucosidase from Sporidiobolus pararoseus: characterization and application in winemaking.
abstract: For the first time, the production of an extracellular β-glucosidase (Sp-β-gl) by a Sporidiobolus pararoseus yeast strain is reported. The Sp-β-gl activity was quantified, characterized, and assessed for its efficiency in releasing aroma-enhancing compounds in wines. The maximum enzymatic synthesis was after 72 h of growth in a complex media with 20 g/L of cellobiose. The optimal pH and temperature were 5.5 and at 50 °C, respectively. It showed a wide range of pH stability and exhibited quite high thermostability at low temperatures. In addition, this β-glucosidase revealed tolerance to wine-associated inhibitory compounds (sugars and ethanol), showing suitable characteristics for all the stages of alcoholic fermentation. The hydrolysis of the glycosidic terpenes by Sp-β-gl was studied by gas chromatography, and its ability to efficiently release free terpenols has been demonstrated. The concentrations of geraniol, linalool, α-terpineol, and nerol were significantly increased in treated wines. These results suggest the potential application of this new yeast β-glucosidase as an aroma-enhancing enzyme in winemaking.
  
  
  CONCLUSIONS
  The search for new β-glucosidase from yeast sources is important to improve the quality of wines. In this work, an S. pararoseus yeast strain has shown to be capable to produce a β-glucosidase with suitable combination of properties for functionality in wines and with potential to increase the concentration of free aroma compounds, showing good prospects for an industrial application.
authors.affiliation: Inst de Ciências Ambientais e Agrárias, Univ Federal de Uberlândia, Uberlândia, MG 38405-303, Brazil. millabaffi@yahoo.com.br
authors.forename: Milla A
authors.initials: MA
authors.lastname: Baffi
authors.forename: Thaise
authors.initials: T
authors.lastname: Tobal
authors.forename: João
authors.initials: J
authors.lastname: Henrique
authors.forename: G
authors.initials: G
authors.lastname: Lago
authors.forename: Rodrigo S R
authors.initials: RS
authors.lastname: Leite
authors.forename: Maurício
authors.initials: M
authors.lastname: Boscolo
authors.forename: Eleni
authors.initials: E
authors.lastname: Gomes
authors.forename: Roberto
authors.initials: R
authors.lastname: Da-Silva
mesh_terms: D000080462:Acyclic Monoterpenes; D001487:Basidiomycota / Q000201:enzymology*; D000081005:Cyclohexane Monoterpenes; D053138:Cyclohexenes / Q000032:analysis; D004795:Enzyme Stability; D005285:Fermentation; D005511:Food Handling / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D039821:Monoterpenes / Q000032:analysis; D009812:Odorants / Q000032:analysis; D013696:Temperature; D013729:Terpenes / Q000032:analysis / Q000378:metabolism; D014920:Wine; D001617:beta-Glucosidase / Q000378:metabolism*
chemical_list: D000080462:Acyclic Monoterpenes; D000081005:Cyclohexane Monoterpenes; D053138:Cyclohexenes; D039821:Monoterpenes; D013729:Terpenes; C016775:alpha-terpineol; C018584:linalool; D001617:beta-Glucosidase; C007836:geraniol