Similar Datasets
Project description:Here we report a metatranscriptomic analysis of gene expression and regulation of “Candidatus Accumulibacter”-enriched lab-scale sludge during enhanced biological phosphorus removal (EBPR). Medium density oligonucleotide microarrays were generated with probes targeting most predicted genes hypothesized to be important for the EBPR phenotype. The objectives were to investigate which genes were expressed during EBPR and which genes were differentially expressed between the early stage of anaerobic and aerobic phases (defined as 15 min after acetate addition and 15 min after switching to aeration respectively).
2009-12-31 | GSE17857 | GEO
Project description:In E. faecalis OG1RF, disruption of the ahrC gene encoding a predicted ArgR family transcription factor results in a severe defect in biofilm formation in vitro, as well as significant attenuation of virulence in multiple experimental infection models. Using RNA-seq, we observed ahrC-dependent changes in expression of over 20 genes. AhrC-repressed genes included predicted determinants of arginine catabolism and several other metabolic genes and predicted transporters, while AhrC-activated genes included determinants involved in production of surface protein adhesins. Most notably, the structural and regulatory genes of the ebp locus encoding adhesive pili were positively regulated, as well as the ace gene, encoding a collagen binding adhesin. Using lacZ transcription reporter fusions, we determined that ahrC and a second argR transcription factor gene, argR2, both function to activate expression of ebpR, which directly activates transcription of the pilus structural genes. Our data suggest that in wild-type E. faecalis, the low levels of EbpR limit expression of pili, and that biofilm biomass is also limited by the amount of pili expressed by the bacteria. Expression of ace is similarly activated by AhrC and ArgR2, but ace expression is not dependent on EbpR. Our results demonstrate the existence of novel regulatory cascades controlled by a pair of ArgR family transcription factors that may function as a heteromeric protein complex.
2018-07-12 | GSE112936 | GEO
Project description:Biofilms are ubiquitous in nature, forming diverse adherent microbial communities that perform a plethora of functions. Here, we operated two laboratory-scale sequence batch reactors enriched with Candidatus Accumulibacter phosphatis (Accumulibacter) performing enhanced biological phosphorus removal (EBPR). Reactors formed two distinct biofilms, a floccular biofilm, consisting of small, loose, microbial aggregates, and a granular biofilm, forming larger, dense, spherical aggregates. Using metaproteomic methods we investigated the proteomic differences between these two biofilm communities, identifying a total of 2022 unique proteins. Both biofilms contained proteins that were indicative of core EBPR metabolisms and cellular function. To understand the proteomic differences between floccular and granular biofilm communities, we compared protein abundances that were statistically enriched in both biofilm states (alpha level = 0.05). Floccular biofilms were enriched with pathogenic secretion systems suggesting a previously unrecognized, highly competitive, mixed microbial community. Comparatively, granular biofilms revealed a high stress environment with evidence of nutrient starvation, phage predation pressure, extracellular polymeric substance (EPS) synthesis, and increased cell lysis. Granular biofilms enriched outermembrane transport proteins to scavenge the extracellular milieu for amino acids and other metabolites, likely released through cell lysis, to supplement core EBPR metabolic pathways. This study provides the first detailed proteomic comparison between Accumulibacter–enriched floccular and granular biofilm communities, proposes a conceptual model for the granule biofilm, and offers novel insights into granule biofilm formation and stability.
2015-08-24 | PXD002404 | Pride
Project description:Manufactured nanomaterials (MNMs) are increasingly incorporated into consumer products that are disposed into sewage. In wastewater treatment, MNMs adsorb to activated sludge biomass where they may impact biological wastewater treatment performance, including nutrient removal. Here, we studied MNM effects on bacterial polyhydroxyalkanoate (PHA), specifically polyhydroxybutyrate (PHB), biosynthesis because of its importance to enhanced biological phosphorus (P) removal (EBPR). Activated sludge was sampled from an anoxic selector of a municipal wastewater treatment plant (WWTP), and PHB-containing bacteria were concentrated by density gradient centrifugation. After starvation to decrease intracellular PHB stores, bacteria were nutritionally augmented to promote PHB biosynthesis while being exposed to either MNMs (TiO2 or Ag) or to Ag salts (each at a concentration of 5 mg L-1). Cellular PHB concentration and PhyloChip community composition were analyzed. The final bacterial community composition differed from activated sludge, demonstrating that laboratory enrichment was selective. Still, PHB was synthesized to near-activated sludge levels. Ag salts altered final bacterial communities, although MNMs did not. PHB biosynthesis was diminished with Ag (salt or MNMs), indicating the potential for Ag-MNMs to physiologically impact EBPR through the effects of dissolved Ag ions on PHB producers.
2014-12-03 | GSE63781 | GEO
Project description:EBPR full cycle of Ca. Accumulibacter SCUT-4 (0,20,40,80,116,152min))
| PXD056138 |
Project description:Manufactured nanomaterials (MNMs) are increasingly incorporated into consumer products that are disposed into sewage. In wastewater treatment, MNMs adsorb to activated sludge biomass where they may impact biological wastewater treatment performance, including nutrient removal. Here, we studied MNM effects on bacterial polyhydroxyalkanoate (PHA), specifically polyhydroxybutyrate (PHB), biosynthesis because of its importance to enhanced biological phosphorus (P) removal (EBPR). Activated sludge was sampled from an anoxic selector of a municipal wastewater treatment plant (WWTP), and PHB-containing bacteria were concentrated by density gradient centrifugation. After starvation to decrease intracellular PHB stores, bacteria were nutritionally augmented to promote PHB biosynthesis while being exposed to either MNMs (TiO2 or Ag) or to Ag salts (each at a concentration of 5 mg L-1). Cellular PHB concentration and PhyloChip community composition were analyzed. The final bacterial community composition differed from activated sludge, demonstrating that laboratory enrichment was selective. Still, PHB was synthesized to near-activated sludge levels. Ag salts altered final bacterial communities, although MNMs did not. PHB biosynthesis was diminished with Ag (salt or MNMs), indicating the potential for Ag-MNMs to physiologically impact EBPR through the effects of dissolved Ag ions on PHB producers. 18 samples; Triplicate PHB-enriched bacterial communities recovered from activated sludge were exposed to nanoparticle (TiO2 or Ag) or AgNO3 (as a silver control) or were not exposed to an nanoparticles (control) to determine if the naoparticles affected PHB production.
2014-12-03 | E-GEOD-63781 | biostudies-arrayexpress
Project description:EBPR bioreactor sludge Metagenome
| PRJNA231882 | ENA