Ontology highlight
ABSTRACT:
PROVIDER: PRJNA761368 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Bacteria growing in biofilms are physiologically heterogeneous, due in part to their adaptation to local environmental conditions. Here, we characterized the local transcriptional responses of Pseudomonas aeruginosa growing in biofilms by using microarray analysis of isolated biofilm subpopulations. The results demonstrated that cells at the top of the biofilms had high mRNA abundances for genes involved in general metabolic functions, while mRNAs for these housekeeping genes were low in cells at the bottom of the biofilms. Selective GFP labeling showed that cells at the top of the biofilm were actively dividing. However, the dividing cells had high mRNAs levels for genes regulated by the hypoxia induced regulator, Anr. Slow-growing cells deep in the biofilms had little expression of Anr-regulated genes and may have experienced long-termanoxia. Transcripts for ribosomal proteins were primarily associated with the metabolically active cell fraction, while ribosomal RNAs were abundant throughout the biofilms, indicating that ribosomes are stably maintained even in slowly growing cells. Consistent with these results was the identification of mRNAs for ribosome hibernation factors (rmf and PA4463) at the bottom of the biofilms. A P. aeruginosa ∆rmf strain had increased uptake of the membrane integrity stain, propidium iodide. Using selective GFP labeling and cell sorting, we showed that the dividing cells were more susceptible to tobramycin and ciprofloxacin than the dormant subpopulation. The results demonstrate that in thick P. aeruginosa biofilms, cells are physiologically distinct spatially, with cells deep in the biofilm in a viable but antibiotic-tolerant slow-growth state.
2012-05-03 | GSE34762 | GEO
Project description:Tor Caldara is a shallow-water gas vent located in the Mediterranean Sea, with active venting of CO 2 , H 2 S. At Tor Caldara, filamentous microbial biofilms, mainly composed of Epsilon- and Gammaproteobacteria, grow on substrates exposed to the gas venting. In this study, we took a metaproteogenomic approach to identify the metabolic potential and in situ expression of central metabolic pathways at two stages of biofilm maturation. Our findings indicate that inorganic reduced sulfur species are the main electron donors and CO 2 the main carbon source for the filamentous biofilms, which conserve energy by oxygen and nitrate respiration, fix dinitrogen gas and detoxify heavy metals. Three metagenome-assembled genomes (MAGs), representative of key members in the biofilm community, were also recovered. Metaproteomic data show that metabolically active chemoautotrophic sulfide-oxidizing members of the Epsilonproteobacteria dominated the young microbial biofilms, while Gammaproteobacteria become prevalent in the established community. The co-expression of different pathways for sulfide oxidation by these two classes of bacteria suggests exposure to different sulfide concentrations within the biofilms, as well as fine-tuned adaptations of the enzymatic complexes. Taken together, our findings demonstrate a shift in the taxonomic composition and associated metabolic activity of these biofilms in the course of the colonization process.
2021-01-25 | PXD023357 | Pride
Project description:Microbial EPS production from various substrates
| PRJEB39763 | ENA
Project description:Bacteria growing in biofilms are physiologically heterogeneous, due in part to their adaptation to local environmental conditions. Here, we characterized the local transcriptional responses of Pseudomonas aeruginosa growing in biofilms by using microarray analysis of isolated biofilm subpopulations. The results demonstrated that cells at the top of the biofilms had high mRNA abundances for genes involved in general metabolic functions, while mRNAs for these housekeeping genes were low in cells at the bottom of the biofilms. Selective GFP labeling showed that cells at the top of the biofilm were actively dividing. However, the dividing cells had high mRNAs levels for genes regulated by the hypoxia induced regulator, Anr. Slow-growing cells deep in the biofilms had little expression of Anr-regulated genes and may have experienced long-termanoxia. Transcripts for ribosomal proteins were primarily associated with the metabolically active cell fraction, while ribosomal RNAs were abundant throughout the biofilms, indicating that ribosomes are stably maintained even in slowly growing cells. Consistent with these results was the identification of mRNAs for ribosome hibernation factors (rmf and PA4463) at the bottom of the biofilms. A P. aeruginosa M-bM-^HM-^Frmf strain had increased uptake of the membrane integrity stain, propidium iodide. Using selective GFP labeling and cell sorting, we showed that the dividing cells were more susceptible to tobramycin and ciprofloxacin than the dormant subpopulation. The results demonstrate that in thick P. aeruginosa biofilms, cells are physiologically distinct spatially, with cells deep in the biofilm in a viable but antibiotic-tolerant slow-growth state. 52-hour Pseudomonas aeruginosa TSA colony biofilms were cryoembedded, thin sectioned, and laser dissected (LCM) to obtain samples from the top and bottom 50 M-BM-5m of the biofilms. 9 sections per biofilm were pooled. RNA was extracted with the RNeasy Micro kit, Turbo DNase treated, poly(A) tailed, and amplified using the Quantitect WTA kit. After clean up, the resulting product was fragmented and end labeled before hybridization.
2012-05-02 | E-GEOD-34762 | biostudies-arrayexpress
Project description:The physiological and transcriptional response of Nitrosomonas europaea biofilms to phenol and toluene was examined and compared to suspended cells. Biofilms were grown in Drip Flow Biofilm Reactors under continuous flow conditions of growth medium containing ammonia as growth substrate. The responses of N. europaea biofilms to the aromatic hydrocarbons phenol and toluene were determined during short-term (3 h) additions of each compound to the biofilms. Ammonia oxidation in the biofilms was inhibited 50% by 60 uM phenol and 100 uM toluene. These concentrations were chosen for microarray analysis of phenol- and toluene-exposed N. europaea biofilms. Liquid batch cultures of exponentially growing N. europaea cells were harvested alongside the biofilms to determine differential gene expression between attached and suspended growth of N. europaea.
2010-07-20 | GSE22646 | GEO