title: Inducible gene expression in Lactobacillus reuteri LTH5531 during type II sourdough fermentation.
abstract: Lactobacillus reuteri LTH5531 is a dominant member of the microbiota of type II sourdough fermentations. To investigate the genetic background of the ecological performance of LTH5531, in vivo expression technology was used to identify promoters that show elevated levels of expression during growth of this organism in a type II sourdough fermentation. Thirty-eight sourdough-induced fusions were detected, and 29 genes could be identified on the basis of the available sequence information. Four genes encoded stress-related functions (e.g., acid and general stress response), reflecting the harsh conditions prevailing during sourdough fermentation. Further, eight genes were involved in acquisition and synthesis of amino acids and nucleotides, indicating their limited availability in sourdough. The remaining genes were either part of functionally unrelated pathways or encoded hypothetical proteins. The identification of a putative proteinase and a component of the arginine deiminase pathway is of technological interest, as they are potentially involved in the formation of aroma precursors. Our study allowed insight into the transcriptional response of Lactobacillus reuteri to the dough environment, which establishes the molecular basis to investigate bacterial properties that are likely to contribute to the ecological performance of the organism and influence the final outcome of the fermentation.
authors.affiliation: Institute of Food Technology, University of Hohenheim, Garbenstr. 28, D-70599 Stuttgart, Germany.
authors.forename: Fabio
authors.initials: F
authors.lastname: Dal Bello
authors.forename: Jens
authors.initials: J
authors.lastname: Walter
authors.forename: Stefan
authors.initials: S
authors.lastname: Roos
authors.forename: Hans
authors.initials: H
authors.lastname: Jonsson
authors.forename: Christian
authors.initials: C
authors.lastname: Hertel
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001939:Bread / Q000382:microbiology*; D005285:Fermentation; D015964:Gene Expression Regulation, Bacterial; D015723:Gene Library; D007778:Lactobacillus / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins