title: Transcription profiling of interactions between Lactococcus lactis subsp. cremoris SK11 and Lactobacillus paracasei ATCC 334 during Cheddar cheese simulation.
abstract: The starter cultures (Lactococcus sp.) and non-starter lactic acid bacteria (mostly Lactobacillus spp.) are essential to flavor development of Cheddar cheese. The aim of this study was to elucidate the transcriptional interaction between Lactococcus lactis subsp. cremoris SK11 and Lactobacillus paracasei ATCC 334 in mixed cultures during simulated Cheddar cheese manufacture (Pearce activity test) and ripening (slurry). Reverse transcription quantitative PCR (RT-qPCR) was used to quantify the expression of 34 genes common to both bacteria and for eight genes specific to either L. lactis subsp. cremoris SK11 or L. paracasei ATCC 334. The multifactorial analysis (MFA) performed on fold change results for each gene revealed that the genes linked to stress, protein and peptide degradation as well as carbohydrate metabolism of L. paracasei ATCC 334 were especially overexpressed in mixed culture with L. lactis subsp. cremoris SK11 during the ripening simulation. For L. lactis subsp. cremoris SK11, genes coding for amino acid metabolism were more expressed during the cheese manufacture simulation, especially in single culture. These results show how complementary functions of starter and NSLAB contribute to activities useful for flavor development.
authors.affiliation: Institut sur la nutrition et les aliments fonctionnels (INAF), Département des Sciences des aliments et de nutrition, Université Laval, G1V 0A6 QC, Canada.
authors.forename: Émilie
authors.initials: É
authors.lastname: Desfossés-Foucault
authors.affiliation: Institut sur la nutrition et les aliments fonctionnels (INAF), Département des Sciences des aliments et de nutrition, Université Laval, G1V 0A6 QC, Canada.
authors.forename: Gisèle
authors.initials: G
authors.lastname: LaPointe
authors.affiliation: Institut sur la nutrition et les aliments fonctionnels (INAF), Département des Sciences des aliments et de nutrition, Université Laval, G1V 0A6 QC, Canada. Electronic address: denis.roy@inaf.ulaval.ca.
authors.forename: Denis
authors.initials: D
authors.lastname: Roy
mesh_terms: D000818:Animals; D002611:Cheese / Q000032:analysis / Q000382:microbiology*; D016000:Cluster Analysis; D005516:Food Microbiology; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D007778:Lactobacillus / Q000235:genetics* / Q000378:metabolism; D013294:Lactococcus lactis / Q000235:genetics* / Q000378:metabolism; D008892:Milk / Q000382:microbiology; D016133:Polymerase Chain Reaction; D013649:Taste
keywords: Cheddar cheese; Interaction; Lactic acid bacteria; Transcription profile