Project description:A heterotrophic ammonia-oxidizing bacterium Alcaligenes sp. HO-1 was isolated from the activated sludge of a bioreactor treating ammonia-rich piggery wastewater. The goal and objectives of this experiment are to analyze the transcriptome profiles of nitrogen-metabolism-related genes of Alcaligenes sp. HO-1 in response to ammonium stimulation over time and to find out potential genes involved in ammonia oxidation process. So the RNA-seq anaylsis was performed by setting up each time points (0, 3.5, 10, 22 hours) when strain HO-1 were exposed to ammonia. HO-1 was cultured with 83 mM succinate and 14 mM ammonium sulfate until ammonia was completely consumed and then another 14 mM of ammonium sulfate was added to the culture. Cells were harvested at 0 h, 3.5 h, 10 h and 22 h after the addition of ammonium sulfate. The sequencing data of RNAs obtained from strain HO-1 cells at each time was analyzed.
2022-05-20 | GSE174685 | GEO
Project description:Resistance and recovery mechanism of heterotrophic ammonia assimilation system under chromium hexavalent stress
| PRJNA1079040 | ENA
Project description:Heterotrophic ammonia assimilation system regulated by hydraulic retention time
| PRJNA1177651 | ENA
Project description:Comparison of autotrophic nitrogenation and heterotrophic ammonia assimilation biosystems under sulfamethoxazole Stress
| PRJNA1283971 | ENA
Project description:Novel insights into the intrinsic mechanism of magnetic field on the enhancement of long-term performance of anammox process
Project description:Detecting chemical signals is important for identifying food sources and avoiding harmful agents. Like many animals, C. elegans use olfaction to chemotax towards their main food source, bacteria. However, little is known about the bacterial compounds governing C. elegans attraction to bacteria and the physiological importance of these compounds to bacteria. Here, we address these questions by investigating the function of a small RNA, P11, in the pathogen, Pseudomonas aeruginosa, that was previously shown to mediate learned pathogen avoidance. We discovered that this RNA also affects the attraction of untrained C. elegans to P. aeruginosa and does so by controlling production of ammonia, a volatile odorant produced during nitrogen assimilation. We describe the complex regulation of P. aeruginosa nitrogen assimilation, which is mediated by a partner-switching mechanism involving environmental nitrates, sensor proteins, and P11. In addition to mediating C. elegans attraction, we demonstrate that nitrogen assimilation mutants perturb bacterial fitness and pathogenesis during C. elegans infection by P. aeruginosa. These studies define ammonia as a major mediator of trans-kingdom signaling, implicate nitrogen assimilation as important for both bacteria and host organisms, and highlight how a bacterial metabolic pathway can either benefit or harm a host in different contexts.
Project description:The widespread use of electricity raises the question of whether or not 50 Hz (power line frequency in Europe) magnetic fields (MFs) affect organisms. We investigated the transcription of Escherichia coli K-12 MG1655 in response to extremely low-frequency (ELF) MFs. Fields generated by three signal types (sinusoidal continuous, sinusoidal intermittent, and power line intermittent; all at 50 Hz, 1 mT), were applied and gene expression was monitored at the transcript level using an Affymetrix whole-genome microarray. Bacterial cells were grown continuously in a chemostat (dilution rate D = 0.4 h-1) fed with glucose-limited minimal medium and exposed to 50 Hz MFs with a homogenous flux density of 1 mT. For all three types of MFs investigated, neither bacterial growth (determined using optical density) nor culturable counts were affected. Likewise, no statistically significant change (fold-change > 2, P ≤ 0.01) in the expression of 4,358 genes and 714 intergenic regions represented on the gene chip was detected after MF exposure for 2.5 h (1.4 generations) or 15 h (8.7 generations). Moreover, short-term exposure (8 min) to the sinusoidal continuous and power line intermittent signal neither affected bacterial growth nor showed evidence for reliable changes in transcription. In conclusion, our experiments did not indicate that the different tested MFs (50 Hz, 1 mT) affected the transcription of E. coli. A total of 60 chips are included in this study. Each comparison (treated vs. sham-treated cultures; untreated negative control cultures) consists of three replicates. The three magnetic field test conditions include sinusoidal continous, sinusoidal intermittent (2 min on, 4 min off) and power line intermittent (2 min on, 4 min off). Exposure periods were 8 min, 2.5 h, or 15 h. The response control consists of E. coli cells treated for 10 min with 1 mM H2O2 or the equivalent water volume. The negative control comprises samples taken from cultures grown with the exposure chambers swiched off.
Project description:To investigate the relevant biological mechanism involved in the inhibition of 143B cells when cultured with injectable magnetothermal bioactive systems (IMBSs) under alternating magnetic field (AMF), the high-throughput RNA sequencing was conducted.
Project description:The ammonia-oxidizing bacterium Nitrosomonas europaea has been widely recognized as an important player in the nitrogen cycle as well as one of the most abundant members in microbial communities for the treatment of industrial or sewage wastewater. Its natural metabolic versatility and extraordinary ability to degrade environmental pollutants enable it to thrive under various harsh environmental conditions. This model of N. europaea (iGC535) is the most accurate metabolic model for a nitrifying organism to date, reaching an average prediction accuracy of over 90% under several growth conditions. The manually curated model can predict phenotypes under chemolithotrophic and chemolithoorganotrophic conditions while oxidating methane and wastewater pollutants.
It is the first upload of the model.
Project description:Physiological and molecular evidences have shown earlier that low CO2 might have been a major driving force during the evolution of C4 photosynthesis, not only being a selection pressure but also as a signaling agent. However, a mechanistic linkage between low CO2 and C4 emergence is missing. In this study, using transcriptomics study in model plant Arabidopsis thaliana, we demonstrated that under long-term low CO2 treatments, the up-regulation of C4 related genes were linked to the up-regulation of genes involved in photorespiration, nitrogen assimilation and glycolysis. Plants under low CO2 also showed altered d13C. The carbonic anhydrase (CA), phosphoenolpyruvate carboxylase (PEPC), malate dehydrogenase (MDH), glutamine oxoglutarate aminotransferase (GS-GOGAT), which are required to reassimilate ammonia, were up-regulated under low CO2. Furthermore, under low CO2, genes involved in PEP regeneration from glycolysis were up-regulated while pyruvate orthophosphate dikinase (PPDK) was down-regulated, suggesting a route of PEP regeneration from glycolysis. All these results suggested that under long-term low CO2 treatment, the selection pressure to recapture the released ammonia from the increased photorespiration might have promoted the evolution of mechanisms for generation PEP from glycolysis and enhancement of enzymes catalyzing formation of oxaloacetate, one intermediate which can accept ammonia residue. These adjustments in metabolism provide a mechanistic linkage between low CO2 and evolution of C4 photosynthesis.