title: Community dynamics of bacteria in sourdough fermentations as revealed by their metatranscriptome.
abstract: The lactic acid bacterial (LAB) community dynamics of two wheat and two spelt sourdough fermentations that were daily back-slopped were monitored during a period of 10 days by hybridizing time-related RNA samples, representing the metatranscriptome, to an LAB functional gene microarray. To indicate the species present in each hybridized sample, annotation information for the 2,269 oligonucleotides on the microarray was used. The overall hybridization data revealed that after a transition phase of 5 days, in which atypical sourdough LAB species, including Enterococcus species, were found, a stabilized ecosystem was established with Lactobacillus plantarum and Lactobacillus fermentum as the dominating LAB species. Compared with the combined outcome of culture-dependent and culture-independent identification techniques, the microarray data revealed a functional role for Lactococcus lactis in the early stage ecosystem and the dominance of Pediococcus pentosaceus in most of the fermentations, besides L. plantarum and L. fermentum. Consequently, metatranscriptome hybridization data obtained using an LAB functional gene microarray was shown to be an interesting alternative to microbiological analysis of the community dynamics of complex food ecosystems.
authors.affiliation: Research Group of Industrial Microbiology and Food Biotechnology (IMDO), Faculty of Sciences and Bio-engineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, Brussels, Belgium.
authors.forename: Stefan
authors.initials: S
authors.lastname: Weckx
authors.forename: Roel
authors.initials: R
authors.lastname: Van der Meulen
authors.forename: Joke
authors.initials: J
authors.lastname: Allemeersch
authors.forename: Geert
authors.initials: G
authors.lastname: Huys
authors.forename: Peter
authors.initials: P
authors.lastname: Vandamme
authors.forename: Paul
authors.initials: P
authors.lastname: Van Hummelen
authors.forename: Luc
authors.initials: L
authors.lastname: De Vuyst
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000254:growth & development / Q000302:isolation & purification*; D044822:Biodiversity; D017753:Ecosystem; D005285:Fermentation; D005516:Food Microbiology; D020869:Gene Expression Profiling; D054892:Metagenome; D046228:Microarray Analysis / Q000379:methods; D013997:Time Factors; D014908:Triticum