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.
Project description:The ability of Microlunatus phosphovorus to accumulate large amounts of polyphosphate (Poly-P) plays an important role in removing soluble phosphorus from wastewater. Our analyses indicate that Microlunatus phosphovorus accumulates Poly-P under aerobic conditions but releases phosphorus under anaerobic conditions. To determine the mechanisms underlying Poly-P metabolism, we compared transcriptional profiles under aerobic and anaerobic conditions. Significant differences were detected in the expression levels of genes associated with Poly-P metabolism between aerobic and anaerobic conditions. These findings enhance our understanding of phosphate metabolism in a major bacterial species involved in wastewater phosphorus reduction.
2017-11-15 | GSE106860 | GEO
Project description:Treatment of pyrethroids-containing wastewater
Project description:Polycyclic aromatic hydrocarbons (PAHs) are widely distributed pollutants. As in saturated PAH-contaminated sites oxygen is rapidly depleted, microorganisms able to use these compounds as a carbon source in the absence of molecular oxygen are crucial for their consumption. Here, we described the metabolic pathway for anaerobic degradation of phenanthrene by a sulfate-reducing enrichment culture (TRIP) obtained from a natural asphalt lake. The dominant organism of this culture belongs to the Desulfobacteraceae family of deltaproteobacteria. Proteogenome analysis revealed that the metabolic capacity of this bacterium includes the key enzymes for dissimilatory sulfate reduction, the Embden-Meyerhof-Parnas pathway, a complete tricarboxylic acid cycle as well as the key elements of the Wood-Ljungdahl pathway. Genes encoding enzymes potentially involved in the degradation of phenanthrene were identified in the genome of this bacterium. Two gene clusters were identified encoding a carboxylase enzyme involved in the activation of phenanthrene, as well as genes encoding reductases potentially involved in subsequent ring dearomatization and reduction steps. The predicted metabolic pathways were corroborated by transcriptome and proteome analyses and provide the first metabolic pathway for anaerobic degradation of three-rings PAHs.
Project description:Soil humic substances are known to positively influence plant growth and nutrition. In particular, low-molecular fractions have been shown to increase NO3- uptake and PM H+-ATPase activity and alter expression of related genes. Changes in maize root transcriptome due to treatment with nitrate (NO3-), Water-Extractable Humic Substances (WEHS) and NO3-+WEHS were analyzed.
2018-07-30 | GSE103184 | GEO
Project description:Insight into Ferrihydrite Effects on Methanogenesis in UASB Reactor Treating High Sulfate Wastewater: Microbial Community
Project description:Three surface waters in Gainesville, Florida were used in a 48 hour whole effluents exposure to assess gene expression profiles of male fathead minnow liver. Microarray analysis was used to determine changes in gene expression of exposed fish to waters from a site downstream of a wastewater treatment plant (streamwater), a wastewater treatment plant (wastewater), and a lake (stormwater). Differences in gene expression between fish exposed to collected waters and controls were observed. Number of altered genes and biological processes were 1028 and 18 for stormwater; 787 and 19 for streamwater; and: 575 and 12 for wastewater. In general, the effects observed in all exposed fish were related with fatty acid metabolism, DNA repair, oxidation-reduction process, cell wall catabolic process and apoptosis. All exposed fish showed altered expression of genes related with DNA damage repair. In particular fish exposed to stormwater and streamwater showed downregulation of several key intermediates transcripts of cholesterol. The presence and environmental persistence of perfluorinated chemicals (PFCs) in these waters, the resemblance in known effects on transcripts with those found in this study, suggest that the set of genes differentially regulated in fathead minnows after 48 hours of exposure may be attributed to exposure to PFCs.
2012-04-25 | GSE37550 | GEO
Project description:Anaerobic Treatment of Dairy Wastewater
| PRJNA601960 | ENA
Project description:anaerobic treatment of animal wastewater
Project description:Humic substances are principal components of soil organic matter. They have ecological importance as they intervene in regulating a large number of chemical and biological processes that occur in natural ecosystems. Their ability to improve plant growth has been well established in diverse plant species and growth conditions, although the mechanism responsible for this biological action is poorly understood. Microarray analysis might give us more information about up or down regulation of different biological processes. Wheat plants have been grown hydroponically and treated with Humic acid. Seeds were germinated in obscurity during 10 days, and grown in nutrient solution during 10 days. Harvests were conducted 24 hours, 72 hours and 30 days after treatment application, in order to study early response or a more sustained effect during time.