title: The carbohydrate metabolism signature of lactococcus lactis strain A12 reveals its sourdough ecosystem origin.
abstract: Lactococcus lactis subsp. lactis strain A12 was isolated from sourdough. Combined genomic, transcriptomic, and phenotypic analyses were performed to understand its survival capacity in the complex sourdough ecosystem and its role in the microbial community. The genome sequence comparison of strain A12 with strain IL1403 (a derivative of an industrial dairy strain) revealed 78 strain-specific regions representing 23% of the total genome size. Most of the strain-specific genes were involved in carbohydrate metabolism and are potentially required for its persistence in sourdough. Phenotype microarray, growth tests, and analysis of glycoside hydrolase content showed that strain A12 fermented plant-derived carbohydrates, such as arabinose and α-galactosides. Strain A12 exhibited specific growth rates on raffinose that were as high as they were on glucose and was able to release sucrose and galactose outside the cell, providing soluble carbohydrates for sourdough microflora. Transcriptomic analysis identified genes specifically induced during growth on raffinose and arabinose and reveals an alternative pathway for raffinose assimilation to that used by other lactococci.
authors.affiliation: Université de ToulouseUniversité Paul Sabatier, Toulouse, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Passerini
authors.forename: Michèle
authors.initials: M
authors.lastname: Coddeville
authors.forename: Pascal
authors.initials: P
authors.lastname: Le Bourgeois
authors.forename: Pascal
authors.initials: P
authors.lastname: Loubière
authors.forename: Paul
authors.initials: P
authors.lastname: Ritzenthaler
authors.forename: Catherine
authors.initials: C
authors.lastname: Fontagné-Faucher
authors.forename: Marie-Line
authors.initials: ML
authors.lastname: Daveran-Mingot
authors.forename: Muriel
authors.initials: M
authors.lastname: Cocaign-Bousquet
mesh_terms: D015373:Bacterial Typing Techniques; D050260:Carbohydrate Metabolism / Q000235:genetics*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005285:Fermentation; D005516:Food Microbiology; D016680:Genome, Bacterial; D006026:Glycoside Hydrolases / Q000032:analysis; D013294:Lactococcus lactis / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D059467:Transcriptome
chemical_list: D004269:DNA, Bacterial; D006026:Glycoside Hydrolases