Project description:b-Oxidative enzymes for fatty acid degradation (Fad) of long-chain fatty acid (LCFA), a component of lung surfactant phosphatidylcholine, are induced in vivo during lung infection in cystic fibrosis patients, which could contribute to nutrient acquisition and pathogenesis of Pseudomonas aeruginosa. In addition, fatty acid biosynthesis (Fab) is essential for the syntheses of two virulence controlling acylated-homoserine-lactone molecules in this organism. We mapped the promoter regions of the fadBA5-operon (PA3014 and PA3013) and a fadE homologue (PA2815) involved in Fad and the fabAB-operon involved in Fab. Focusing on the transposon mutagenesis of strain PAO1 carrying the PfadBA5-lacZ fusion, we identified a regulator for the fadBA5-operon to be PsrA (PA3006). Transcriptome analysis of the DpsrA mutant indicates its importance in regulating b-oxidative enzymes, which confirms a previous proteomic study. We further showed that induction of the fadBA-operon responds to LCFA signals, and this induction requires the presence of PsrA, suggesting that PsrA binds to LCFA to derepress fadBA5. Electrophoresis mobility shift assay indicate specific binding of PsrA to the fadBA5-promoter region. This binding is disrupted by specific LCFA (C18:1D9, C16:0, and to a lesser extent C14:0), but not by the first intermediate of b-oxidation, acyl-CoA. We proposed that PsrA is a Fad-regulator that binds and responds to LCFA signals in Pseudomonas aeruginosa. Experiment Overall Design: PAO1 and PAO1-psrA::Tn cultures grown in LB and cells were harvested at mid-log phase. Total RNA was isolated from both samples, and used for cDNA synthesis. And then, the cDNA for both samples were fragmented and labeled. The cDNA of PAO1 was used for 2 GeneChips, and PAO1-psrA::Tn cDNA was used for three GeneChips.
Project description:b-Oxidative enzymes for fatty acid degradation (Fad) of long-chain fatty acid (LCFA), a component of lung surfactant phosphatidylcholine, are induced in vivo during lung infection in cystic fibrosis patients, which could contribute to nutrient acquisition and pathogenesis of Pseudomonas aeruginosa. In addition, fatty acid biosynthesis (Fab) is essential for the syntheses of two virulence controlling acylated-homoserine-lactone molecules in this organism. We mapped the promoter regions of the fadBA5-operon (PA3014 and PA3013) and a fadE homologue (PA2815) involved in Fad and the fabAB-operon involved in Fab. Focusing on the transposon mutagenesis of strain PAO1 carrying the PfadBA5-lacZ fusion, we identified a regulator for the fadBA5-operon to be PsrA (PA3006). Transcriptome analysis of the DpsrA mutant indicates its importance in regulating b-oxidative enzymes, which confirms a previous proteomic study. We further showed that induction of the fadBA-operon responds to LCFA signals, and this induction requires the presence of PsrA, suggesting that PsrA binds to LCFA to derepress fadBA5. Electrophoresis mobility shift assay indicate specific binding of PsrA to the fadBA5-promoter region. This binding is disrupted by specific LCFA (C18:1D9, C16:0, and to a lesser extent C14:0), but not by the first intermediate of b-oxidation, acyl-CoA. We proposed that PsrA is a Fad-regulator that binds and responds to LCFA signals in Pseudomonas aeruginosa. Keywords: Pseudomonas aeruginosa, wild-type PAO1 compared to PAO1-psrA::Tn
2008-02-14 | GSE8083 | GEO
Project description:Inoculum for degradation of LCFA-containing wastewater at low temperature
Project description:Global transcriptomics analysis of the Desulfovibrio vulgaris change from syntrophic growth with Methanosarcina barkeri to sulfidogenic metabolism
Project description:Long chain fatty acids (LCFA) serve as energy sources, components of cell membranes, and precursors for signalling molecules. Here we show that these important biological compounds also regulate gene expression by controlling the transcriptional activities of the retinoic acid (RA)-activated nuclear receptors RAR and PPARβ/δ. Our data indicates that these activities of LCFA are mediated by FABP5, a protein that delivers ligands from the cytosol to nuclear PPARβ/δ. Both saturated and unsaturated LCFA (SLCFA, ULCFA) tightly bind to FABP5, thereby displacing RA and diverting it to RAR. However, while SLCFA inhibit, ULCFA activate the FABP5/PPARβ/δ pathway. By concomitantly promoting the activation of RAR and inhibiting the activity of PPARβ/δ, SLCFA suppress the growth and oncogenic properties of FABP5-expressing carcinoma cells both in cultured cells and in vivo.
Project description:A combination of shotgun metaproteomics and 16S rRNA gene pyrosequencing wasused to identify potential functional pathways and key microorganisms involved in long-chain fatty acids (LCFA) anaerobic conversion. Microbial communities degrading saturated- and unsaturated-LCFA were compared. Archaeal communities were mainly composed of Methanosaeta, Methanobacterium and Methanospirillum species, both in stearate (saturated C18:0) and oleate (mono-unsaturated C18:1) incubations. Over 80% of the 16S rRNA gene sequences clustered within the Methanosaeta genus, which is in agreement with the high number of proteins assigned to this group (94%). Archaeal proteins related with methane metabolism were highly expressed. Bacterial communities were rather diverse and the composition dissimilar between incubations with saturated- and unsaturated-LCFA. Stearate-degrading communities were enriched in Deltaproteobacteria (34% of the assigned sequences), while microorganisms clustering within the Synergistia class were more predominant in oleate incubation (25% of the assigned sequences). Bacterial communities were diverse and active, given by the high percentage of proteins related with mechanisms of energy production. Several proteins were assigned to syntrophic bacteria, emphasizing the importance of the interactions between acetogens and methanogens in energy exchange and formation in anaerobic LCFA-rich environments.
Project description:A combination of shotgun metaproteomics and 16S rRNA gene pyrosequencing wasused to identify potential functional pathways and key microorganisms involved in long-chain fatty acids (LCFA) anaerobic conversion. Microbial communities degrading saturated- and unsaturated-LCFA were compared. Archaeal communities were mainly composed of Methanosaeta, Methanobacterium and Methanospirillum species, both in stearate (saturated C18:0) and oleate (mono-unsaturated C18:1) incubations. Over 80% of the 16S rRNA gene sequences clustered within the Methanosaeta genus, which is in agreement with the high number of proteins assigned to this group (94%). Archaeal proteins related with methane metabolism were highly expressed. Bacterial communities were rather diverse and the composition dissimilar between incubations with saturated- and unsaturated-LCFA. Stearate-degrading communities were enriched in Deltaproteobacteria (34% of the assigned sequences), while microorganisms clustering within the Synergistia class were more predominant in oleate incubation (25% of the assigned sequences). Bacterial communities were diverse and active, given by the high percentage of proteins related with mechanisms of energy production. Several proteins were assigned to syntrophic bacteria, emphasizing the importance of the interactions between acetogens and methanogens in energy exchange and formation in anaerobic LCFA-rich environments.
Project description:A combination of shotgun metaproteomics and 16S rRNA gene pyrosequencing wasused to identify potential functional pathways and key microorganisms involved in long-chain fatty acids (LCFA) anaerobic conversion. Microbial communities degrading saturated- and unsaturated-LCFA were compared. Archaeal communities were mainly composed of Methanosaeta, Methanobacterium and Methanospirillum species, both in stearate (saturated C18:0) and oleate (mono-unsaturated C18:1) incubations. Over 80% of the 16S rRNA gene sequences clustered within the Methanosaeta genus, which is in agreement with the high number of proteins assigned to this group (94%). Archaeal proteins related with methane metabolism were highly expressed. Bacterial communities were rather diverse and the composition dissimilar between incubations with saturated- and unsaturated-LCFA. Stearate-degrading communities were enriched in Deltaproteobacteria (34% of the assigned sequences), while microorganisms clustering within the Synergistia class were more predominant in oleate incubation (25% of the assigned sequences). Bacterial communities were diverse and active, given by the high percentage of proteins related with mechanisms of energy production. Several proteins were assigned to syntrophic bacteria, emphasizing the importance of the interactions between acetogens and methanogens in energy exchange and formation in anaerobic LCFA-rich environments.
Project description:A combination of shotgun metaproteomics and 16S rRNA gene pyrosequencing wasused to identify potential functional pathways and key microorganisms involved in long-chain fatty acids (LCFA) anaerobic conversion. Microbial communities degrading saturated- and unsaturated-LCFA were compared. Archaeal communities were mainly composed of Methanosaeta, Methanobacterium and Methanospirillum species, both in stearate (saturated C18:0) and oleate (mono-unsaturated C18:1) incubations. Over 80% of the 16S rRNA gene sequences clustered within the Methanosaeta genus, which is in agreement with the high number of proteins assigned to this group (94%). Archaeal proteins related with methane metabolism were highly expressed. Bacterial communities were rather diverse and the composition dissimilar between incubations with saturated- and unsaturated-LCFA. Stearate-degrading communities were enriched in Deltaproteobacteria (34% of the assigned sequences), while microorganisms clustering within the Synergistia class were more predominant in oleate incubation (25% of the assigned sequences). Bacterial communities were diverse and active, given by the high percentage of proteins related with mechanisms of energy production. Several proteins were assigned to syntrophic bacteria, emphasizing the importance of the interactions between acetogens and methanogens in energy exchange and formation in anaerobic LCFA-rich environments.