Ammonia oxidation by the enrichment culture "Candidatus Nitrosacidococcus tergens" sp. RJ19 across a pH gradient from pH 2.5 to 7.0
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB95883 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Ammonia oxidation was considered impossible under highly acidic conditions, as the protonation of ammonia leads to decreased substrate availability and formation of toxic nitrogenous compounds. Recently, some studies described archaeal and bacterial ammonia oxidizers growing at pH as low as 4, while environmental studies observed nitrification at even lower pH values. In this work, we report on the discovery, cultivation, and physiological, genomic, and transcriptomic characterization of a novel gammaproteobacterial ammonia-oxidizing bacterium enriched via continuous bioreactor cultivation from an acidic air biofilter that was able to grow and oxidize ammonia at pH 2.5. This microorganism has a chemolithoautotrophic lifestyle, using ammonia as energy source. The observed growth rate on ammonia was 0.196 day-1, with a doubling time of 3.5 days. The strain also displayed ureolytic activity and cultivation with urea as ammonia source resulted in a growth rate of 0.104 day-1 and a doubling time of 6.7 days. A high ammonia affinity (Km(app) = 147 ± 14 nM) and high tolerance to toxic nitric oxide could represent an adaptation to acidic environments. Electron microscopic analysis showed coccoid cell morphology with a large amount of intracytoplasmic membrane stacks, typical of gammaproteobacterial ammonia oxidizers. Furthermore, genome and transcriptome analysis showed the presence and expression of diagnostic genes for nitrifiers (amoCAB, hao, nor, ure, cbbLS), but no nirK was identified. Phylogenetic analysis revealed that this strain belonged to a novel bacterial genus, for which we propose the name "Candidatus Nitrosacidococcus tergens" sp. RJ19.
| S-EPMC8115276 | biostudies-literature
Project description:Microbial low pH Mn(II) oxidation
| PRJEB11431 | ENA
Project description:Intracellular pH (pHi) dynamics regulates diverse cell processes such as proliferation, dysplasia, and differentiation, often mediated by the protonation state of a functionally critical histidine residue in endogenous pH sensing proteins. How pHi dynamics can directly regulate gene expression and whether transcription factors can function as pH sensors has received limited attention. We tested the prediction that transcription factors with a histidine in their DNA binding domain (DBD) that forms hydrogen bonds with nucleotides can have pH-regulated activity, which is relevant to more than 85 transcription factors in distinct families, including FOX, KLF, SOX and MITF/Myc. Focusing on FOX family transcription factors, we used unbiased SELEX-seq to identify pH-dependent DNA binding motif preferences, then confirm pH-regulated binding affinities for FOXC2, FOXM1, and FOXN1 to a canonical FkhP DNA motif that are 2.5 to 7.5 greater at pH 7.0 compared with pH 7.5. For FOXC2, we also find greater activity for an FkhP motif at lower pHi in cells and that pH-regulated binding and activity are dependent on a conserved histidine (His122) in the DBD. RNA-seq with FOXC2 also reveals pH-dependent differences in enriched promoter motifs. Our findings identify pH-regulated transcription factor-DNA binding selectivity with relevance to how pHi dynamics can regulate gene expression for myriad cell behaviours.
2024-06-24 | GSE270316 | GEO
Project description:Intracellular pH (pHi) dynamics regulates diverse cell processes such as proliferation, dysplasia, and differentiation, often mediated by the protonation state of a functionally critical histidine residue in endogenous pH sensing proteins. How pHi dynamics can directly regulate gene expression and whether transcription factors can function as pH sensors has received limited attention. We tested the prediction that transcription factors with a histidine in their DNA binding domain (DBD) that forms hydrogen bonds with nucleotides can have pH-regulated activity, which is relevant to more than 85 transcription factors in distinct families, including FOX, KLF, SOX and MITF/Myc. Focusing on FOX family transcription factors, we used unbiased SELEX-seq to identify pH-dependent DNA binding motif preferences, then confirm pH-regulated binding affinities for FOXC2, FOXM1, and FOXN1 to a canonical FkhP DNA motif that are 2.5 to 7.5 greater at pH 7.0 compared with pH 7.5. For FOXC2, we also find greater activity for an FkhP motif at lower pHi in cells and that pH-regulated binding and activity are dependent on a conserved histidine (His122) in the DBD. RNA-seq with FOXC2 also reveals pH-dependent differences in enriched promoter motifs. Our findings identify pH-regulated transcription factor-DNA binding selectivity with relevance to how pHi dynamics can regulate gene expression for myriad cell behaviours.
2024-06-24 | GSE270232 | GEO
Project description:Intracellular pH (pHi) dynamics regulates diverse cell processes such as proliferation, dysplasia, and differentiation, often mediated by the protonation state of a functionally critical histidine residue in endogenous pH sensing proteins. How pHi dynamics can directly regulate gene expression and whether transcription factors can function as pH sensors has received limited attention. We tested the prediction that transcription factors with a histidine in their DNA binding domain (DBD) that forms hydrogen bonds with nucleotides can have pH-regulated activity, which is relevant to more than 85 transcription factors in distinct families, including FOX, KLF, SOX and MITF/Myc. Focusing on FOX family transcription factors, we used unbiased SELEX-seq to identify pH-dependent DNA binding motif preferences, then confirm pH-regulated binding affinities for FOXC2, FOXM1, and FOXN1 to a canonical FkhP DNA motif that are 2.5 to 7.5 greater at pH 7.0 compared with pH 7.5. For FOXC2, we also find greater activity for an FkhP motif at lower pHi in cells and that pH-regulated binding and activity are dependent on a conserved histidine (His122) in the DBD. RNA-seq with FOXC2 also reveals pH-dependent differences in enriched promoter motifs. Our findings identify pH-regulated transcription factor-DNA binding selectivity with relevance to how pHi dynamics can regulate gene expression for myriad cell behaviours.
2025-04-04 | GSE293822 | GEO
Project description:I-motifs (iMs) are four-stranded non-B DNA structures containing C-rich DNA sequences, which can be formed under various pH conditions. DNA methylation exhibits complex impacts on iM formation in vitro. However, how DNA methylation differentially affects pH dependent iM formation on a genome wide scale is completely uncharacterized in both humans and plants. To this end, we conducted iM-IP-seq under pH 5.5 and 7.0 conditions using CK and hyper/hypomethylated DNA in combination with BS-seq in rice. We found that pH 7.0 and 5.5 biased iMs had distinct genomic features and differential DNA methylation levels, the former having higher DNA methylation levels than the latter. Moreover, DNA demethylation and hyper methylation had more impacts on a subset of iM formation under pH 7.0 and 5.5, respectively, indicating that DNA de/hyper-methylation exhibits pH dependent impacts on iM formation. Importantly, we found that CG hypo-DMRs and CHH hyper-DMRs alone or coordinated with CG/CHG hyper-DMRs may play determinant roles in the regulation of iM formation under pH 5.5 and 7.0. Thus, our study shows that intrinsic DNA sequences alone or in combination with DNA methylation play vital roles in determining pH-dependent formation of iMs. It will contribute to in-depth understanding of DNA methylation in the modulation of pH dependent dynamics of iM conformation, therefore broadening its biological implications and practical application ranges.
2024-02-15 | GSE234751 | GEO
Project description:I-motifs (iMs) are four-stranded non-B DNA structures containing C-rich DNA sequences, which can be formed under various pH conditions. DNA methylation exhibits complex impacts on iM formation in vitro. However, how DNA methylation differentially affects pH dependent iM formation on a genome wide scale is completely uncharacterized in both humans and plants. To this end, we conducted iM-IP-seq under pH 5.5 and 7.0 conditions using CK and hyper/hypomethylated DNA in combination with BS-seq in rice. We found that pH 7.0 and 5.5 biased iMs had distinct genomic features and differential DNA methylation levels, the former having higher DNA methylation levels than the latter. Moreover, DNA demethylation and hyper methylation had more impacts on a subset of iM formation under pH 7.0 and 5.5, respectively, indicating that DNA de/hyper-methylation exhibits pH dependent impacts on iM formation. Importantly, we found that CG hypo-DMRs and CHH hyper-DMRs alone or coordinated with CG/CHG hyper-DMRs may play determinant roles in the regulation of iM formation under pH 5.5 and 7.0. Thus, our study shows that intrinsic DNA sequences alone or in combination with DNA methylation play vital roles in determining pH-dependent formation of iMs. It will contribute to in-depth understanding of DNA methylation in the modulation of pH dependent dynamics of iM conformation, therefore broadening its biological implications and practical application ranges.
2024-02-15 | GSE234750 | GEO
Project description:Transcriptional profiling of Helicobacter pylori comparing 26695 wild-type strain and a HP0244-deficient mutant 26695/∆HP0244::km treated at three different pH conditions (pH 7.4, pH 4.5 without urea, or pH 2.5 with 30 mM urea) for 30 min to define the HP0244 acid-responsive regulon Keywords: Genetic modification and stress response
2009-09-14 | GSE12900 | GEO
Project description:The purpose of this study was to examine how Mtb integrates acidic pH and available carbon sources as environmental cues to regulate its metabolism and growth rate. RNA-seq transcriptional profiling of M. tuberculosis growing at acidic or neutral pH, in pyruvate or glycerol, was examined. These studies identified carbon source-dependent and -independent pH-dependent adaptations. Mtb strain CDC1551 was grown in standing T-75 flasks in 40 mL of medium seeded an initial OD of 0.1. We examined medium in four conditions pH 7.0 10 mM glycerol, pH 5.7 10 mM glycerol, pH 7.0 10 mM pyruvate, pH 5.7 10 mM pyruvate. Following 3 days of incubation at 37C, RNA was isolated from the bacterial cultures and used for RNA-seq.
2014-07-07 | E-GEOD-52020 | biostudies-arrayexpress
Project description:Gene expression profiles of Escherichia coli K-12 W3110 were compared as a function of steady-state external pH. Cultures were grown with aeration to an optical density at 600 nm of 0.3 in potassium-modified Luria-Bertani medium buffered at pH 5.0, 7.0, and 8.7. For each of the three pH conditions, cDNA from RNA of five independent cultures was hybridized to Affymetrix E. coli arrays. Analysis of variance with a significance level of 0.001 resulted in 98% power to detect genes showing a twofold difference in expression. Normalized expression indices were calculated for each gene and intergenic region (IG). Differential expression among the three pH classes was observed for 763 genes and 353 IGs. Hierarchical clustering yielded six well-defined clusters of pH profiles, designated Acid High (highest expression at pH 5.0), Acid Low (lowest expression at pH 5.0), Base High (highest at pH 8.7), Base Low (lowest at pH 8.7), Neutral High (highest at pH 7.0, lower in acid or base), and Neutral Low (lowest at pH 7.0, higher at both pH extremes). Flagellar and chemotaxis genes were repressed at pH 8.7 (Base Low cluster), where the cell's transmembrane proton potential is diminished by the maintenance of an inverted pH gradient. High pH also repressed the proton pumps cytochrome o (cyo) and NADH dehydrogenases I and II. By contrast, the proton-importing ATP synthase F1Fo and the microaerophilic cytochrome d (cyd), which minimizes proton export, were induced at pH 8.7. These observations are consistent with a model in which high pH represses synthesis of flagella, which expend proton motive force, while stepping up electron transport and ATPase components that keep protons inside the cell. Acid-induced genes, on the other hand, were coinduced by conditions associated with increased metabolic rate, such as oxidative stress. All six pH-dependent clusters included envelope and periplasmic proteins, which directly experience external pH. Overall, this study showed that (i) low pH accelerates acid consumption and proton export, while coinducing oxidative stress and heat shock regulons; (ii) high pH accelerates proton import, while repressing the energy-expensive flagellar and chemotaxis regulons; and (iii) pH differentially regulates a large number of periplasmic and envelope proteins. Keywords: Steady State
2006-03-23 | GSE4511 | GEO