title: A way to follow the viability of encapsulated Bifidobacterium bifidum subjected to a freeze-drying process in order to target the colon: interest of flow cytometry.
abstract: The aim of this work was to apply flow cytometry in order to assess and compare the viability of freeze-dried entrapped bacteria with an usual technique by quantification by plate count techniques. It also aimed at studying the effect of various cryoprotectants on the viability of an entrapped Bifidobacterium bifidum subjected to freeze-drying to check their ability to be delivered all along the gastro-intestinal tract. The alginate-pectinate beads were chosen as the encapsulation matrix added with different protectants. The beads were characterized by scanning electron microscopy and the viability was checked by both methods. The best combination to improve viability of entrapped bacteria subjected to freeze-drying is made of glycerol 20% (one cryoprotectant) and sodium ascorbate 10% (one anti-oxidative compound). This study also demonstrates that flow cytometry allows assessment of entrapped bacteria viability. Indeed we showed that viability evaluated by plate method is correlated to that obtained by flow cytometry. So, flow cytometry is a rapid method to determine cell viability after encapsulation and freeze-drying. Finally, these beads seem to be a promising probiotic delivery system to target the colon.
authors: Unité Procédés Alimentaires et Microbiologiques (UMR A 02.102), AgroSup Dijon-Université de Bourgogne, 1 esplanade Erasme, 21000 Dijon, France.
authors: F
authors: F
authors: Martin-Dejardin
authors: B
authors: B
authors: Ebel
authors: G
authors: G
authors: Lemetais
authors: H
authors: H
authors: Nguyen Thi Minh
authors: P
authors: P
authors: Gervais
authors: R
authors: R
authors: Cachon
authors: O
authors: O
authors: Chambin
mesh_terms: D000464:Alginates; D058491:Bacterial Load; D001644:Bifidobacterium; D003106:Colon; D003451:Cryoprotective Agents / Q000494:pharmacology; D005434:Flow Cytometry; D005612:Freeze Drying; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D050296:Microbial Viability / Q000187:drug effects; D010368:Pectins
chemical_list: D000464:Alginates; D003451:Cryoprotective Agents; D006603:Hexuronic Acids; D010368:Pectins; D020723:Glucuronic Acid