title: A polyphasic approach to study the dynamics of microbial population of an organic wheat sourdough during its conversion to gluten-free sourdough.
abstract: To develop a method for organic gluten-free (GF) sourdough bread production, a long-term and original wheat sourdough was refreshed with GF flours. The dynamics of the sourdough microbiota during five months of back-slopping were analyzed by classical enumeration and molecular methods, including PCR-temporal temperature gel electrophoresis (PCR-TTGE), multiplex PCR, and pulsed field gel electrophoresis (PFGE). The results showed that the yeast counts remained constant, although Saccharomyces cerevisiae, present in the initial wheat sourdough, was no longer detected in the GF sourdough, while lactic acid bacteria (LAB) counts increased consistently. In the first phase, which was aimed at obtaining a GF sourdough from wheat sourdough, Lactobacillus sanfranciscensis, L. plantarum, and L. spicheri were the main LAB species detected. During the second phase, aimed at maintaining the GF sourdough, the L. plantarum and L. spicheri populations decreased whereas L. sanfranciscensis persisted and L. sakei became the predominant species. Multiplex PCRs also revealed the presence of several L. sakei strains in the GF sourdough. In a search for the origin of the LAB species, PCR-TTGE was performed on the flour samples but only L. sanfranciscensis was detected, suggesting a flour origin for this typical sourdough species. Thus, while replacement of the wheat flour by GF flour influenced the sourdough microbiota, some of the original sourdough LAB and yeast species remained in the GF sourdough.
authors.forename: Emilie
authors.initials: E
authors.lastname: Lhomme
authors.forename: Sandra
authors.initials: S
authors.lastname: Mezaize
authors.forename: Maren Bonnand
authors.initials: MB
authors.lastname: Ducasse
authors.forename: Hubert
authors.initials: H
authors.lastname: Chiron
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Champomier-Vergès
authors.forename: Stéphane
authors.initials: S
authors.lastname: Chaillou
authors.forename: Monique
authors.initials: M
authors.lastname: Zagorec
authors.forename: Xavier
authors.initials: X
authors.lastname: Dousset
authors.forename: Bernard
authors.initials: B
authors.lastname: Onno
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D044822:Biodiversity; D001939:Bread / Q000032:analysis / Q000382:microbiology*; D005285:Fermentation; D005433:Flour / Q000032:analysis / Q000382:microbiology; D005983:Glutens / Q000378:metabolism*; D014908:Triticum / Q000382:microbiology*; D015003:Yeasts / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D005983:Glutens