Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1069988 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Bio-augmentation could be a promising strategy to improve processes for treatment and resource recovery from wastewater. In this study, the Gram-positive bacterium Bacillus subtilis was co-cultured with the microbial communities present in wastewater samples with high concentrations of nitrate or ammonium. Glucose supplementation (1%) was used to boost biomass growth in all wastewater samples. In anaerobic conditions, the indigenous microbial community bio-augmented with B. subtilis was able to rapidly remove nitrate from wastewater. In these conditions, B. subtilis overexpressed nitrogen assimilatory and respiratory genes including NasD, NasE, NarG, NarH, and NarI, which arguably accounted for the observed boost in denitrification. Next, we attempted to use the the ammonium- and nitrate-enriched wastewater samples bio-augmented with B. subtilis in the cathodic compartment of bioelectrochemical systems (BES) operated in anaerobic condition. B. subtilis only had low relative abundance in the microbial community, but bio-augmentation promoted the growth of Clostridium butyricum and C. beijerinckii, which became the dominant species. Both bio-augmentation with B. subtilis and electrical current from the cathode in the BES promoted butyrate production during fermentation of glucose. A concentration of 3.4 g/L butyrate was reached with a combination of cathodic current and bio-augmentation in ammonium-enriched wastewater. With nitrate-enriched wastewater, the BES effectively removed nitrate reaching 3.2 mg/L after 48 h. In addition, 3.9 g/L butyrate was produced. We propose that bio-augmentation of wastewater with B. subtilis in combination with bioelectrochemical processes could both boost denitrification in nitrate-containing wastewater and enable commercial production of butyrate from carbohydrate- containing wastewater, e.g. dairy industry discharges. These results suggest that B. subtilis bio-augmentation in our BES promotes simultaneous wastewater treatment and butyrate production.
2020-05-15 | GSE150480 | GEO
Project description:Geobacter sulfurreducens is a widely explored microorganism recognized by its metabolic versatility able to reduce a number of external electron acceptors. In the present study the capacity of this strain to reduce nitrate was evaluated along with its transcriptomic profile under nitrate-reducing conditions and the catalytic role of Pd nanoparticles on the reductive pathway. Results demonstrated that G. sulfurreducens was able to reduce nitrate and important kinetic differences related to the time response were found among the electron donors used (acetate and hydrogen). When using acetate, a delay response on nitrate reduction of 4 days and reduction of 94% of nitrate was achieved, while nitrite was not detected, and all the nitrogen was recovered as ammonium (79.6 ± 5.7 %). The use of hydrogen as electron donor increased 2-fold the maximum rate of nitrate reduction, leading to 93% reduction of nitrate during the first 20 h with recovery of 45% as ammonium, while nitrite was not detected. In addition, transcriptome profiling analysis of G. sulfurreducens under nitrate-reducing conditions using hydrogen or acetate as an electron donor at 2 and 6 days reveals that a core of 146 genes (69 upregulated and 77 downregulated) are differentially expressed in all conditions. Genes related to nitrogen metabolism, such as nrfA and nrfH, gdhA, and amtB, were upregulated in the incubations and RT-qPCR data confirmed upregulations of these genes. Experiments performed with biologically synthesized Pd (Bio-Pd) + G. sulfurreducens cells demonstrated synergistic input of Bio-Pd and the metabolic capacity of G. sulfurreducens. These results expand the metabolic versatility of G. sulfurreducens, which may have important implications in nitrogen cycling in natural environments and engineered systems.
2023-06-01 | GSE179298 | GEO
Project description:Stress resilience involves numerous brain-wide transcriptional changes. Determining the organization and orchestration of these transcriptional events may reveal novel antidepressant targets, but this remains unexplored. Here, we characterize the resilient transcriptome with co-expression analysis and identify a single transcriptionally-active uniquely-resilient gene network. Zfp189, a previously unstudied zinc finger protein, is the top network key driver and its overexpression in prefrontal cortical (PFC) neurons preferentially activates this network, alters neuronal activity and promotes behavioral resilience. CREB, which binds Zfp189, is the top upstream regulator of this network. To probe CREB-Zfp189 interactions as a network regulatory mechanism, we employ CRISPR-mediated locus-specific transcriptional reprogramming to direct CREB selectively to the Zfp189 promoter. This single molecular interaction in PFC neurons recapitulates the pro-resilient Zfp189-dependent downstream effects on gene network activity, electrophysiology and behavior. These findings reveal an essential role for Zfp189 and a CREB-Zfp189 regulatory axis in mediating a central transcriptional network of resilience.
2019-08-22 | GSE118317 | GEO
Project description:Denitrification, a crucial biochemical pathway prevalent among haloarchaea in hypersaline ecosystems, has garnered considerable attention in recent years due to its ecological implications. Nevertheless, the underlying molecular mechanisms and genetic regulation governing this respiration/detoxification process in haloarchaea remain largely unexplored. In this study, RNA-sequencing was used to compare the transcriptomes of the haloarchaeon Haloferax mediterranei under oxic and denitrifying conditions, shedding light on the intricate metabolic alterations occurring within the cell such as the accurate control of the metal homeostasis. Furthermore, the investigation identifies several genes encoding transcriptional regulators and potential accessory proteins with putative roles in denitrification. Among these are bacterioopsin transcriptional activators, proteins harbouring a domain of unknown function (DUF2249), and a cyanoglobin. Additionally, the study delves into the genetic regulation of denitrification, finding a regulatory motif within promoter regions that activates numerous denitrification-related genes. This research serves as a starting point for future molecular biology studies in haloarchaea, offering a promising avenue to unravel the intricate mechanisms governing haloarchaeal denitrification, a pathway of paramount ecological importance.
2024-04-22 | GSE245042 | GEO