Activated sludge
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA320492 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Understanding microbial community diversity is thought to be crucial for improving process functioning and stabilities of wastewater treatment systems. However, current studies largely focus on taxonomic groups based on 16S rRNA, which are not necessarily linked to functioning, or a few selected functional genes. Here we launched a study to profile the overall functional genes of microbial communities in three full-scale wastewater treatment systems. Triplicate activated sludge samples from each system were analyzed using a high-throughput metagenomics tool named GeoChip 4.2, resulting in the detection of 38,507 to 40,647 functional genes. A high similarity of 75.5% to 79.7% shared genes was noted among the nine samples. Moreover, correlation analyses showed that the abundances of a wide array of functional genes were associated with system performances. For example, the abundances of overall nitrogen cycling genes had a strong correlation to total nitrogen (TN) removal rates (r = 0.7647, P < 0.01). The abundances of overall carbon cycling genes were moderately correlated with COD removal rates (r = 0.6515, P < 0.01). Lastly, we found that influent chemical oxygen demand (COD inf) and total phosphorus concentrations (TP inf), and dissolved oxygen (DO) concentrations were key environmental factors shaping the overall functional genes. Together, the results revealed vast functional gene diversity and some links between the functional gene compositions and microbe-mediated processes.
2014-12-31 | GSE53744 | GEO
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:Advanced nitrogen removal Metagenome
| PRJNA323436 | ENA
Project description:Nitrogen removal by MBR sludge
| PRJNA549156 | ENA
Project description:Lab-scale Enhance Biological Phosphorus Removal Enrichment Culture Raw sequence reads
| PRJNA532338 | ENA
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:A comprehensive in vitro assessment of two commercial metal oxide nanoparticles, TiO2 and ZnO, was performed using human monocyte-derived macrophages (HMDM), monocyte-derived dendritic cells (MDDC), and T cell leukemia-derived cell line (Jurkat). TiO2 nanoparticles were found to be non-toxic whereas ZnO nanoparticles caused dose-dependent cell death. Subsequently, global gene expression profiling was performed to identify signaling pathways underlying the cytotoxicity caused by ZnO nanoparticles. Analysis was done with doses, 1ug/ml and 10ug/ml after 6 and 24 hours of exposure. Interestingly, 2703 genes were significantly differentially expressed in HMDM upon exposure to 10ug/ml ZnO nanoparticles, while in MDDCs only 12 genes were affected. In Jurkat cells, 980 genes were differentially expressed. It is noteworthy that the gene expression of metallothioneins was upregulated in all the three cell types. In addition to the common ZnO-inducible changes, a notable proportion of the genes were regulated in a cell type-specific manner. Using a panel of ZnO nanoparticles, we obtained an additional support that the cellular response to ZnO nanoparticles is caused by particle dissolution. Gene ontology analysis revealed that the top biological processes disturbed in HMDM and Jurkat cells were regulating cell death and growth. In addition, genes controlling immune system development were affected. Bioinformatics assessment showed that the top human disease category associated with ZnO-responsive genes in both HMDM and Jurkat cells was cancer. Overall, the study revealed novel genes and pathways for mediating ZnO nanoparticle-induced toxicity and demonstrated the value of assessing nanoparticle responses through combined transcriptomics and bioinformatics approach. Nanoparticles used in the study: ZnO-1 commercial (IBU-tec advanced materials AG), ZnO-2 (mandelic acid coated ZnO-1), ZnO-3 (mercaptopropyl-trimethoxysilane coated ZnO-1), ZnO-4 (methoxyl coated ZnO), ZnO-5 (diethylene glycol modified ZnO) and ZnO-9 (folic acid modified ZnO). Detailed particle production and characterization data can be found from the articles: Buerki-Thurnherr et al. 2012 Nanotoxicology and Tuomela et al.
2013-07-25 | GSE39330 | GEO