Project description:Trancriptional profiling of GE2-14 ΔaguR mutant strain in which the aguR gene of the agmatine deiminase cluster has been deleted. We compared the expression profiling of GE2-14 cells with the expression profiling of GE2-14 ΔaguR mutant cells. The goal was to determine the effect of the aguR deletion on the transcriptional profiling of GE2-14
Project description:The enzymatic repertoire of starter cultures is important for cheese characteristics but is challenging to characterize due to the high protein and fat concentration, and the semi-solid state of the cheese matrix. This study aimed to generate a protocol to characterize the proteome of bacteria harvested from milk and cheese, to assess the proteome differences between Lactococcus cremoris grown in milk and laboratory medium, and to investigate the proteome adaptation during cheese production and ripening.
Project description:The contribution of small RNAs to the regulation of cell wall defense mechanisms, which play a central role in protecting bacteria from environmental insults, remains poorly understood in Lactococcus cremoris, a paradigmatic organism for studying lactic acid bacteria. Analysis of the profiles of 193 putative sRNAs, including 131 newly identified in this study, revealed altered expression of 20 and 25 sRNAs following treatment with major cell wall-targeting antimicrobials lysozyme and penicillin G, respectively. Further analysis and genome-wide functional screening identified four sRNAs that modulate the lysozyme response in opposite directions, with sLLM1042+, sLLM2-, and sLLM1993+ conferring increased, and sLLM461+ decreased, resistance. Moreover, elevated expression of sLLM2- or sLLM1042+ promoted the sensitivity of cells to penicillin G and certain abiotic stresses, and had pleiotropic effects on gene regulation at both RNA and protein levels, positioning them as key elements in regulatory networks. Notably, the sLLM2- mediated decrease in four putative tellurium resistance proteins resulted in L. cremoris sensitivity to tellurite stress. As sLLM2- mutations, altering lysozyme and penicillin responses, reduce the expression of alanine racemase Alr, we suggest that its upregulation possibly modulates D-alanine levels, thereby affecting lipoteichoic acid modification or peptidoglycan synthesis. Our findings underscored the broad roles of sRNAs in defensive responses to cell wall-targeting antimicrobials in lactic acid bacteria.
Project description:Trancriptional profiling of GE2-14 ?aguR mutant strain in which the aguR gene of the agmatine deiminase cluster has been deleted. We compared the expression profiling of GE2-14 cells with the expression profiling of GE2-14 ?aguR mutant cells. The goal was to determine the effect of the aguR deletion on the transcriptional profiling of GE2-14 Two strains GE2-14 (reference) vs. GE2-14 ?aguR (test) cells in same conditions. Three biological replicates, two technical replicates and one dye swap.
