Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1007374 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Bacterial community structure as affected by mulched fertigation systems in semi-arid area of northeast China
| PRJNA819180 | ENA
Project description:Nitrogen metabolism in Aspergillus nidulans is subject to regulation by the GATA transcription factor AreA which is required for the utilization of a wide range of nitrogen sources other than glutamine or ammonium. The level of AreA activity is regulated by intracellular glutamine levels that vary in response to nitrogen supplementation. For nitrate assimilation, which involves two transporters (CrnA, CrnB), nitrate reductase (NiaD) and nitrite reductase (NiiA), the respective genes are subject to regulation at the level of transcription, including nitrogen metabolite repression mediated by AreA and induction mediated by nitrite or nitrate, mediated by a second transcription factor, NirA. Both transcription factors act synergistically to regulate the expression of all four structural genes when nitrogen is limiting or either nitrate or nitrite is available. In this study we dissect the nitrogen limitation effect mediated by AreA form the nitrate/nitrite specific effect mediated by NirA on the transcriptome level. Keywords: Nitrate/nitrogen limitation response
2009-01-01 | GSE10475 | GEO
Project description:Nitrite-oxidizing bacteria are vital players in the global nitrogen cycle that convert nitrite to nitrate during the 2nd step of nitrification. Within this functional guild, the genus Nitrospira is among the most widespread and phylogenetically and physiologically diverse nitrite oxidizers and its members drive nitrite oxidation in many natural and biotechnological ecosystems. Despite their ecological and biotechnological importance, our understanding of Nitrospira’s energy metabolism is still limited. The main bottleneck for a detailed biochemical characterization of Nitrospira is biomass production, since they are slow-growing organisms and fastidious to culture. In this study, we cultured Nitrospira moscoviensis in a continuous stirred tank reactor system (CSTR) allowing constant biomass harvesting. Additionally, this cultivation setup enabled accurate control of physicochemical parameters and thus avoided fluctuating levels of nitrite and accumulation of nitrate. We performed transcriptome analysis and confirmed constant gene expression profiles in the chemostat culture over a period of two weeks. The transcriptomic data supports the predicted core metabolism of N. moscoviensis, including the reductive TCA cycle as a CO2 fixation pathway, the novel bd-like oxidase as terminal oxidase and the octaheme nitrite reductase involved in nitrogen assimilation. Additionally, the expression of multiple copies of respiratory complexes suggests functional differentiation of these copies within the respiratory chain. Transcriptome analysis also suggests a soluble and a membrane-bound gamma subunit as part of the nitrite oxidoreductase (NXR), the enzyme catalyzing nitrite oxidation. Overall, the transcriptome data provided novel insights into the metabolism of Nitrospira supporting the genome-based prediction of key pathways. Moreover, the application of a CSTR to cultivate Nitrospira is an important foundation for future proteomic and biochemical characterizations, which are crucial for a better understanding of canonical and complete nitrifying microorganisms.
2019-07-03 | GSE123406 | GEO
Project description:Two maize hybrid cultivars contrasting in low nitrogen tolerance (low nitrogen-tolerant XY335 and low nitrogen-sensitive HN178) were used in this study . The experiment was carried out at Xinji Experimental Station (43º31′N, 124º48′E) of Hebei Agricultural University. The top 0-20 cm of the soil used contained organic matter 17.79 g·kg-1, total nitrogen 1.21 g·kg-1, alkali hydrolyzed nitrogen 64.9 mg.kg-1, available phosphorus 23.8 mg·kg-1, and available potassium 120.6 mg·kg-1. The experiment adopted a split plot design, with varieties as the main plot and nitrogen fertilizer as the sub-plot. There were 2 varieties for testing: XY335 and HN138. Two levels of nitrogen supply: N0 (0 kg N ha-1) and N240 (240 kg N ha-1), replicated three times. Each plot had 6 rows, with the row length measuring 20 m, and the row spacing of 60 cm, giving the plot area of 72 m2. The planting density was 67,500 plants ha-1. Nitrogen fertilizer used was urea (46% N), and 50% was applied before sowing and at the flared stage, respectively. During the grain filling stage, leaf tissues of three biological replicates were collected from control and treatment conditions, and immediately frozen in liquid nitrogen for subsequent proteomics analysis.
2022-05-20 | PXD028027 | Pride
Project description:Nitrification, the oxidation of ammonia via nitrite to nitrate, has always been considered to be a two-step process catalysed by chemolithoautotrophic microorganisms oxidizing either ammonia or nitrite. No known nitrifier carries out both steps, although complete nitrification should be energetically advantageous. This functional separation has puzzled microbiologists for a century. Here we report on the discovery and cultivation of a completely nitrifying bacterium from the genus Nitrospira, a globally distributed group of nitrite oxidizers. The genome of this chemolithoautotrophic organism encodes the pathways both for ammonia and nitrite oxidation, which are concomitantly activated during growth by ammonia oxidation to nitrate. Genes affiliated with the phylogenetically distinct ammonia monooxygenase and hydroxylamine dehydrogenase genes of Nitrospira are present in many environments and were retrieved on Nitrospira contigs in new metagenomes from engineered systems. These findings fundamentally change our picture of nitrification and point to completely nitrifying Nitrospira as key components of nitrogen-cycling microbial communities.
2019-03-15 | PXD013103 | Pride