title: Potential probiotic Pichia kudriavzevii strains and their ability to enhance folate content of traditional cereal-based African fermented food.
abstract: With the aim of selecting starter cultures with interesting probiotic potential and with the ability to produce folate in a food matrix, yeast strains isolated from fermented cereal-based African foods were investigated. A total of 93 yeast strains were screened for their tolerance to pH 2 and 0.3% of bile salts. Pichia kudriavzevii isolates gave the best results. Selected P. kudriavzevii strains were tested for survival to the simulated human digestion and for adhesion to Caco-2 cells. Moreover, presence of folate biosynthesis genes was verified and production of extra and intra-cellular folate determined during growth in culture medium. 31% of yeast strains could tolerate pH 2, while 99% bile salts. Survival rate after simulated digestion ranged between 11 and 45%, while adhesion rate between 12 and 40%. Folate production was mainly intracellular, maximum after 24 h of growth. To be closer to traditional cereal-based fermentations, a P. kudriavzevii strain with good probiotic potential was co-inoculated with Lactobacillus fermentum strains in a pearl millet gruel. This resulted in in situ folate production that peaked after 4 h. The use of strains with both probiotic and nutritional enrichment properties may have a greater impact for the consumers.
authors.affiliation: Department of Agricultural, Forest and Food Science, University of Torino, Grugliasco, Italy. Electronic address: anna.greppi@hest.ethz.ch.
authors.forename: Anna
authors.initials: A
authors.lastname: Greppi
authors.affiliation: Institute of Research for Development (IRD), UMR 204 Nutripass, IRD/University of Montpellier/SupAgro, Montpellier, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Saubade
authors.affiliation: Department of Agricultural, Forest and Food Science, University of Torino, Grugliasco, Italy.
authors.forename: Cristian
authors.initials: C
authors.lastname: Botta
authors.affiliation: Institute of Research for Development (IRD), UMR 204 Nutripass, IRD/University of Montpellier/SupAgro, Montpellier, France.
authors.forename: Christèle
authors.initials: C
authors.lastname: Humblot
authors.affiliation: Institute of Research for Development (IRD), UMR 204 Nutripass, IRD/University of Montpellier/SupAgro, Montpellier, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Guyot
authors.affiliation: Department of Agricultural, Forest and Food Science, University of Torino, Grugliasco, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Cocolin
mesh_terms: D000349:Africa; D001647:Bile Acids and Salts; D018938:Caco-2 Cells; D002523:Edible Grain / Q000737:chemistry*; D005285:Fermentation; D005492:Folic Acid / Q000032:analysis* / Q000096:biosynthesis; D005516:Food Microbiology; D005527:Food, Fortified / Q000032:analysis / Q000382:microbiology; D006801:Humans; D052197:Limosilactobacillus fermentum / Q000378:metabolism; D050296:Microbial Viability; D009753:Nutritive Value; D010843:Pichia / Q000302:isolation & purification / Q000502:physiology*; D019936:Probiotics / Q000378:metabolism
chemical_list: D001647:Bile Acids and Salts; D005492:Folic Acid
keywords: Folate; Food enrichment; LAB; Pichia kudriavzevii; Probiotics; Yeasts