title: S. cerevisiae fermentation activity after moderate pulsed electric field pre-treatments.
abstract: The batch fermentation process, inoculated by Pulsed Electric Field (PEF) treated wine yeasts (Saccharomyces cerevisiae Actiflore F33), was studied. PEF treatment was applied to the aqueous yeast suspensions ([Y] = 0.012 g/L) at the electric field strengths of E = 100 and 6000 V/cm using the same treatment protocol (number of pulses n = 1000, pulse duration ti = 100 μs, and pulse repetition time Δt = 100 ms). Electrical conductivity was increasing during and after the PEF treatment, which reflected cell electroporation. Then, fermentation was run for 150 h in an incubator (30 °C) with synchronic agitation. Electro-stimulation was revealing itself by the improvement of fermentation characteristics, and thus increased yeast metabolism. At the end of the lag phase (t = 40 h), fructose consumption in samples with electrically activated inoculum exceeded that of the control samples by ≈ 2.33 times for E = 100 V/cm and by ≈ 3.98 for E = 6000 V/cm. At the end of the log phase (120 h of fermentation), ≈ 30% mass reduction was reached in samples with PEF-treated inocula (E = 6000 V/cm), whereas the same mass reduction of the control sample required approximately 20 extra hours of fermentation.
authors.affiliation: Équipe TAI EA TIMR 4297, Université de Technologie de Compiègne, Centre de Recherche de Royallieu BP 20529-60205 Compiègne Cedex, France; Chemical Engineering Department, University of Balamand, Amioun, Lebanon. Electronic address: jessy.matar@gmail.com.
authors.forename: Jessy R
authors.initials: JR
authors.lastname: Mattar
authors.affiliation: Équipe TAI EA TIMR 4297, École Supérieure de Chimie Organique et Minérale, 1 allée du réseau Jean-Marie Buckmaster 60200 Compiègne Cedex, France.
authors.forename: Mohammad F
authors.initials: MF
authors.lastname: Turk
authors.affiliation: Équipe TAI EA TIMR 4297, Université de Technologie de Compiègne, Centre de Recherche de Royallieu BP 20529-60205 Compiègne Cedex, France.
authors.forename: Maurice
authors.initials: M
authors.lastname: Nonus
authors.affiliation: Équipe TAI EA TIMR 4297, Université de Technologie de Compiègne, Centre de Recherche de Royallieu BP 20529-60205 Compiègne Cedex, France; Department of Physical Chemistry of Disperse Minerals, Institute of Biocolloidal Chemistry, NAS of Ukraine, 42, Blvr. Vernadskogo, Kyiv 03142, Ukraine.
authors.forename: Nikolai I
authors.initials: NI
authors.lastname: Lebovka
authors.affiliation: Chemical Engineering Department, University of Balamand, Amioun, Lebanon.
authors.forename: Henri
authors.initials: H
authors.lastname: El Zakhem
authors.affiliation: Équipe TAI EA TIMR 4297, Université de Technologie de Compiègne, Centre de Recherche de Royallieu BP 20529-60205 Compiègne Cedex, France.
authors.forename: Eugene
authors.initials: E
authors.lastname: Vorobiev
mesh_terms: D061249:Batch Cell Culture Techniques; D004553:Electric Conductivity; D004558:Electric Stimulation; D018274:Electroporation; D005285:Fermentation; D005632:Fructose / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D007700:Kinetics; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D014920:Wine / Q000382:microbiology
chemical_list: D005632:Fructose; D005947:Glucose
keywords: Biomass; Electrostimulation; Fermentation; Pulsed fields; S. cerevisiae