Project description:Transcriptomic analysis of C. jejuni HPC5 grown in anaerobic jar supplemented with air mix and in Modular Atmospheric Controlled System (MAC). C. jejuni HPC5 is a Campylobacter strain isolated from broiler chickens. Majority of the Campylobacter strains are cultured in an atmosphere containing 5-10% (v/v) oxygen or 5% hydrogen and 5-10% (v/v) carbon dioxide and the rest with nitrogen. To set up a jar (3.5L, Oxoid) to the required microaerophilic conditions, a vacuum is created to -22 psi and then air mixture of 85% v/v nitrogen, 10% v/v carbon dioxide and 5% v/v hydrogen (Air Products, Crewe, UK) is introduced into the jar. This resulted in a microaerobic atmosphere containing approximately 5.6% oxygen, 3.6% hydrogen, 7.3% carbon dioxide and 83% nitrogen. The Modular Atmospheric Controlled System (MAC; Don Whitely Scientific) is an anaerobic chamber where air mixture of 85% nitrogen, 10% carbon dioxide and 5% oxygen is used for growing Campylobacter. Differences in growth pattern were observed when Campylobacters were grown in it and transcriptomic analysis was done to prove the difference in the regulation of genes in the two conditions.
2011-04-01 | GSE17801 | GEO
Project description:Enhanced adaptability of pyrite-based constructed wetlands for low carbon to nitrogen ratio wastewater treatments: modulation of nitrogen removal mechanisms and reduction of carbon emissions
Project description:Low oxygen tensions are often encountered in flooded soils of rice fields by root-associated, strictly respiratory, beta proteobacterium, Azoarcus sp. BH72 which fixes nitrogen only under microaerobic condition. In this study, genome wide oligonucleotide microarrays were used compare the global transcription profile of Azoarcus sp. BH72 under microaerobic condition with cells grown under aerobic condition, both with ammonia as sole nitrogen source. The outcome of this study will provide a better insight about the establishment of this endophyte in the microaerobic environment, probably prevailing inside of the rice root niche .
2014-09-13 | GSE61387 | GEO
Project description:carbon, nitrogen removal and methano utilization Other
Project description:Transcriptomic analysis of C. jejuni HPC5 grown in anaerobic jar supplemented with air mix and in Modular Atmospheric Controlled System (MAC). C. jejuni HPC5 is a Campylobacter strain isolated from broiler chickens. Majority of the Campylobacter strains are cultured in an atmosphere containing 5-10% (v/v) oxygen or 5% hydrogen and 5-10% (v/v) carbon dioxide and the rest with nitrogen. To set up a jar (3.5L, Oxoid) to the required microaerophilic conditions, a vacuum is created to -22 psi and then air mixture of 85% v/v nitrogen, 10% v/v carbon dioxide and 5% v/v hydrogen (Air Products, Crewe, UK) is introduced into the jar. This resulted in a microaerobic atmosphere containing approximately 5.6% oxygen, 3.6% hydrogen, 7.3% carbon dioxide and 83% nitrogen. The Modular Atmospheric Controlled System (MAC; Don Whitely Scientific) is an anaerobic chamber where air mixture of 85% nitrogen, 10% carbon dioxide and 5% oxygen is used for growing Campylobacter. Differences in growth pattern were observed when Campylobacters were grown in it and transcriptomic analysis was done to prove the difference in the regulation of genes in the two conditions. There are three biological replicates for each experiment. Seven independent cDNA preps of C. jejuni HPC5 were prepared and they were labelled independently using AF555 (Fisher, UK). The labelled cDNAs were mixed together and this acted as the control. C. jejuni HPC5 was grown both in the Jar and in the MAC and their cDNAs were labelled independently with AF645 (Fisher, UK). Hybridisations were done between C. jejuni HPC5 grown in jar and in MAC in triplicates. The supplementary file (linked at the foot of this record) represents the averaged normalised values for each experimental condition (3replicates/experimental condition).
Project description:Facultative phototrophic bacteria are excellent models for analyzing the coordination of major metabolic traits including oxidative phosphorylation, photophosphorylation, carbon dioxide fixation and nitrogen fixation. In Rhodobacter sphaeroides and R. capsulatus, a two-component system called RegBA (PrrBA) controls these functions and it has been thought that this redox sensing regulatory system was essential for coordinating electron flow and could not be easily replaced in facultative phototrophs. Here we show that this is not the case and that the oxygen-sensing FixlJ-K system, initially described in rhizobia, controls microaerobic respiration, photophosphorylation and several other metabolic traits in Rhodopseudomonas palustris. A R. palustris fixK mutant grew normally aerobically but was impaired in microaerobic growth. It was also severely impaired in photosynthetic growth and has very little bacteriochlorophyll. Transcriptome analyses indicated that FixK positively regulates heme and bacteriochlorophyll biosynthesis, cbb3 oxidase and NADH dehydrogenase genes, as well as genes for hydrogen uptake, iron oxidation, and aromatic compound degradation. Electrophoretic mobility shift assays showed that FixK binds directly to the promoters of a bacteriochlorophyll biosynthesis operon, a bacteriophytochrome-histidine kinase gene and the fnr-type regulatory gene, aadR. AadR is likely responsible for mediating some indirect effects of FixK on expression of anaerobic genes. These results underscore that physiologically similar bacteria can use very different regulatory strategies to control common major metabolisms.
Project description:RNA-seq of three different Yarrowia lipolytica strains: OKYL029 (control, W29 derived), OKYL049 (high-lipid producing strain), JFYL007 (or Q4, no-lipid producing strain). The strains were grown on DELFT media containing either ammonium sulphate or urea as nitrogen sources. DELFT media had two different carbon-to-nitrogen (C/N) ratios: a nitrogen limiting ratio of 116 and a carbon limiting ratio of 3. The experiments were performed in chemostats, with two different dilution rates of 0,06 and 0,1. Every condition was performed in quadruplicate, and triplicates were selected for RNA-seq.
Project description:In response to limited nitrogen and abundant carbon sources, diploid Saccharomyces cerevisiae strains undergo a filamentous transition in cell growth as part of pseudohyphal differentiation. Use of the disaccharide maltose as the principal carbon source, in contrast to the preferred nutrient monosaccharide glucose, has been shown to induce a hyper-filamentous growth phenotype in a strain deficient for GPA2 which codes for a Galpha protein component that interacts with the glucose-sensing receptor Gpr1p to regulate filamentous growth. In this report, we compare the global transcript and proteomic profiles of wild-type and Gpa2p deficient diploid yeast strains grown on both rich and nitrogen starved maltose media. We find that deletion of GPA2 results in significantly different transcript and protein profiles when switching from rich to nitrogen starvation media. The results are discussed with a focus on the genes associated with carbon utilization, or regulation thereof, and a model for the contribution of carbon sensing/metabolism-based signal transduction to pseudohyphal differentiation is proposed. Keywords: Saccharomyces cerevisiae, nitrogen starvation, maltose, pseudohyphal differentiation, yeast, expression profiling
Project description:Understanding microbial community diversity is thought to be crucial for improving process functioning and stabilities of wastewater treatment systems. However, current studies largely focus on taxonomic groups based on 16S rRNA, which are not necessarily linked to functioning, or a few selected functional genes. Here we launched a study to profile the overall functional genes of microbial communities in three full-scale wastewater treatment systems. Triplicate activated sludge samples from each system were analyzed using a high-throughput metagenomics tool named GeoChip 4.2, resulting in the detection of 38,507 to 40,647 functional genes. A high similarity of 75.5% to 79.7% shared genes was noted among the nine samples. Moreover, correlation analyses showed that the abundances of a wide array of functional genes were associated with system performances. For example, the abundances of overall nitrogen cycling genes had a strong correlation to total nitrogen (TN) removal rates (r = 0.7647, P < 0.01). The abundances of overall carbon cycling genes were moderately correlated with COD removal rates (r = 0.6515, P < 0.01). Lastly, we found that influent chemical oxygen demand (COD inf) and total phosphorus concentrations (TP inf), and dissolved oxygen (DO) concentrations were key environmental factors shaping the overall functional genes. Together, the results revealed vast functional gene diversity and some links between the functional gene compositions and microbe-mediated processes.