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ABSTRACT:
PROVIDER: PRJNA704773 | ENA |
REPOSITORIES: ENA
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Project description:biofilm metagenome Raw sequence reads PHBV denitrification system treat high nitrate concentration
| PRJNA388124 | ENA
Project description:DHS microbial community changes during start-up period
| PRJDB10728 | ENA
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:Microbes in biofilms face the challenge of substrate limitation. In particular, cells in Pseudomonas aeruginosa biofilms growing in the laboratory or during host colonization often become limited for oxygen. Previously we found that phenazines, antibiotics produced by P. aeruginosa, balance the intracellular redox state for cells in biofilms. Here, we show that genes involved in denitrification are induced in phenazine-null (Δphz) mutant biofilms grown under an aerobic atmosphere, even in the absence of nitrate. This finding suggests that resident cells employ a bet-hedging strategy to anticipate the potential availability of nitrate and counterbalance their highly reduced redox state. Consistent with our previous characterization of aerobically-grown colonies supplemented with nitrate, we find that the pathway that is induced in Δphz colonies combines the nitrate reductase activity of the periplasmic enzyme Nap with downstream reduction of nitrite to nitrogen gas catalyzed by the enzymes Nir, Nor, and Nos. This regulatory relationship differs from the denitrification pathway that functions under anaerobic growth with nitrate as the terminal electron acceptor, which depends on the membrane-associated nitrate reductase Nar. We identify sequences in the promoter regions of the nap and nir operons that are required for the effects of phenazines on expression. We also show that specific phenazines have differential effects on nap gene expression. Finally, we provide evidence that individual steps of the denitrification pathway are catalyzed at different depths within aerobically grown biofilms, suggesting metabolic cross-feeding between community subpopulations. (corresponding publication)
2018-10-19 | PXD008924 | Pride
Project description:Transcriptional profiling of Haloarcula hispanica comparing PHB with 960. PHB represents the PHA synthase genes mutant (i.e., ΔphaEC) which is deficient in PHBV accumulation when grown in MG medium. 960 represents the wild-type strain which can produce PHBV when grown in MG medium. Goal was to explore the PHBV biosynthesis and its impact on central metabolism in H. hispanica.
2013-01-22 | GSE42799 | GEO
Project description:Transcriptional profiling of Haloferax mediterranei comparing control wild-type strain with ΔphaEC strain, in which PHA synthase genes are knockouted. ΔphaEC strain is deficient in PHBV accumulation. Goal was to explore the PHBV biosynthetic pathway and to determine their impact on primary metabolism in H. mediterranei.
2012-04-20 | GSE37421 | GEO
Project description:Brain transcriptome at 0h, 1h, 3h, 6h, 12h, 24h, 48h after hypoxia stress Large yellow croakers (body weight at 90-100 g) were purchased from the mariculture farm in Ningde, Fuzhou, China. The fish were maintained at 25 °C in aerated water tanks (dissolved oxygen concentration: 7.8±0.5 mg per liter) with a flow through seawater supply. After 7 days of acclimation, these fish were used for the following experiments. Hypoxic time-course experiments were conducted at 25 °C using published method 30, by bubbling nitrogen gas into an aquarium. The desired pO2 was controlled by using dissolved oxygen meter (, Canada). At the onset of the time course, the oxygen content of the tank was lowered from an aerated pO2 of 100% (7.8 mg per liter) down to 20% (1.6±0.2 mg per liter) over a 30-min period. At the 1-, 3-, 6-, 12-, 24-, and 48-h time points, fish were sampled and sequenced.
2015-04-17 | E-GEOD-57608 | biostudies-arrayexpress
Project description:Because nitrogen (N) nutrition is a key determinant of plant growth, we explored the role of N availability in grafted grapevine development. Vitis vinifera cv. Cabernet Sauvignon was grafted on two rootstock genotypes known to confer high (1103 Paulsen, 1103P) and low (Riparia Gloire de Montpellier, RGM) vigour. One-year-old plants were cultivated in sand-filled pots in a greenhouse and irrigated with the control nutrient solution for 15 days of acclimation (1.6 mM N). At the end of the acclimation period (0 days post treatment (dpt)), the plants were divided in two groups of 5 plants per combination and irrigated with nutrient solutions varying only in their nitrate concentration (0.8 mM (Nitrate -) and 2.45 mM (Nitrate +)). Roots were harvested at 15 and 60 dpt. Gene expression profiling was done using the Nimblegen whole genome array with 3 biological replicates per condition to analyze the combined effect of N treatment and rootstock genotype on gene expression.
2016-04-01 | E-MTAB-3062 | biostudies-arrayexpress