title: Use of whey protein beads as a new carrier system for recombinant yeasts in human digestive tract.
abstract: A new immobilizing protocol using whey protein isolates was developed to entrap recombinant Saccharomyces cerevisiae. The model yeast strain expresses the heterologous P45073A1 that converts trans-cinnamic acid into p-coumaric acid. Beads resulted from a cold-induced gelation of a whey protein solution (10%) containing yeasts (7.5 x 10(7)cells ml(-1)) into 0.1M CaCl(2). The viability and growth capability of yeasts were not altered by our entrapment process. The release and activity of immobilized yeasts were studied in simulated human gastric conditions. During the first 60 min of digestion, 2.2+/-0.9% (n=3) of initial entrapped yeasts were recovered in the gastric medium suggesting that beads should cross the gastric barrier in human. The P45073A1 activity of entrapped yeasts remained significantly higher (p<0.05) than that of free ones throughout digestion (trans-cinnamic acid conversion rate of 63.4+/-1.6% versus 51.5+/-1.8% (n=3) at 120 min). The protein matrix seemed to create a microenvironment favoring the activity of yeasts in the stringent gastric conditions. These results open up new opportunities for the development of drug delivery system using recombinant yeasts entrapped in whey protein beads. The main potential medical applications include biodetoxication or the correction of digestive enzyme deficiencies.
authors.affiliation: Université Clermont1, UFR Pharmacie, Centre de Recherche en Nutrition Humaine (CRNH), Equipe de Recherche Technologique Conception, Ingénierie et Développement de l'Aliment et du Médicament (ERT CIDAM), Clermont-Ferrand F-63001, France.
authors.forename: Géraldine
authors.initials: G
authors.lastname: Hébrard
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Blanquet
authors.forename: Eric
authors.initials: E
authors.lastname: Beyssac
authors.forename: Gabriel
authors.initials: G
authors.lastname: Remondetto
authors.forename: Muriel
authors.initials: M
authors.lastname: Subirade
authors.forename: Monique
authors.initials: M
authors.lastname: Alric
mesh_terms: D001187:Artificial Organs / Q000382:microbiology; D018914:Cells, Immobilized; D016503:Drug Delivery Systems / Q000379:methods*; D041981:Gastrointestinal Tract; D006801:Humans; D008894:Milk Proteins / Q000138:chemical synthesis / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000008:administration & dosage*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D000067816:Whey Proteins; D015002:Yeast, Dried / Q000008:administration & dosage*
chemical_list: D008894:Milk Proteins; D011994:Recombinant Proteins; D000067816:Whey Proteins