de Jong, Anne4; Hansen, Morten Ejby1; Kuipers, Oscar P.4; Kilstrup, Mogens1; Kok, Jan4
1 Department of Systems Biology, Technical University of Denmark2 Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark3 Center for Systems Microbiology, Department of Systems Biology, Technical University of Denmark4 University of Groningen
In the present study we examine the changes in the expression of genes of Lactococcus lactis subspecies cremoris MG1363 during growth in milk. To reveal which specific classes of genes (pathways, operons, regulons, COGs) are important, we performed a transcriptome time series experiment. Global analysis of gene expression over time showed that L. lactis adapted quickly to the environmental changes. Using upstream sequences of genes with correlated gene expression profiles, we uncovered a substantial number of putative DNA binding motifs that may be relevant for L. lactis fermentative growth in milk. All available novel and literature-derived data were integrated into network reconstruction building blocks, which were used to reconstruct and visualize the L. lactis gene regulatory network. This network enables easy mining in the chrono-transcriptomics data. A freely available website at http://milkts.molgenrug.nl gives full access to all transcriptome data, to the reconstructed network and to the individual network building blocks.