ABSTRACT: The multispecies was obtained from a Anoxic-Oxic-Settling-Anaerobic sludge reduction process and a Anoxic-Oxic process in the laboratory Targeted Locus (Loci)
Project description:This SuperSeries is composed of the following subset Series: GSE15272: Diurnally synchronized transitions between oxic and anoxic physiologies in an archaeon, experiment "A" GSE15273: Diurnally synchronized transitions between oxic and anoxic physiologies in an archaeon, experiment "B" GSE15274: Diurnally synchronized transitions between oxic and anoxic physiologies in an archaeon, experiment "Control-1" GSE15275: Diurnally synchronized transitions between oxic and anoxic physiologies in an archaeon, experiment "C" GSE15276: Diurnally synchronized transitions between oxic and anoxic physiologies in an archaeon, experiment "Control-2" Refer to individual Series
Project description:The aim of this study is to investigate the transcriptional response of S. Typhimurium to heat, osmotic, oxidative and acid stress under anoxic and oxic conditions and to non-stressed anoxic conditions.
Project description:In order to ensure the reproducibility of the transcriptional response of Halobacterium NRC-1 to oxic/anoxic transitions, we repeated global mRNA measurements for the oxygen time series data in GSE5924, except that cultures were equilibrated to high oxygen for 12 hours prior to the start of the experiment rather than low oxygen. The results of these data suggest that there is good (~60%) reproducibility between datasets, and that Halobacterium responds robustly to oxic/anoxic transitions. Keywords: time series
Project description:Propionate is an abundant carboxylic acid in nature. Microorganisms metabolize propionate aerobically via the 2-methylcitrate pathway. This pathway depends on a series of three reactions in the citric acid cycle that leads to the conversion of succinate to oxaloacetate. Interestingly, the gamma-proteobacterium Escherichia coli can use propionate as a carbon and electron source under oxic but not under anoxic conditions. The typical downregulation of the citric acid cycle under anoxic conditions is only partially responsible for the inability to use propionate under anoxic conditions since an arcA mutant shows very limited growth on propionate. RT-PCR and transcriptomic analysis revealed a post-transcriptional regulation of the prp-genecluster encoding the necessary enzymes for propionate metabolism. The polycistronic mRNA was hydrolyzed in the 3`-5` direction under anoxic conditions. This regulatory strategy is highly constructive because the last gene of the operon encodes the first enzyme of the propionate metabolism. Further analysis revealed that RNase R catalyzes the hydrolysis of the prp transcripts. Consequently, an rnr-deletion strain could metabolize propionate under anoxic conditions. To the best of our knowledge, this is the first study describing the influence of RNase R on the anaerobic metabolism of E. coli.
Project description:Salmonella enterica var. Typhimurium (S. Typhimurium) is a Gram-negative, facultative intracellular pathogen that infects the intestinal tracts of humans and animals. In the host, S. Typhimurium encounters a wide range of oxygen concentrations going from oxic conditions in the stomach to near anoxic conditions in the distal sigmoid colon-rectal junction. In Escherichia coli, FNR (Fumarate Nitrate Reductase) is one of the main regulatory proteins involved in oxygen sensing and in controlling the transcription of the genes required for the aerobic/anaerobic transition.. However, the role of FNR in S. Typhimurium is largely unknown. To assess its role in S. Typhimurium, we constructed an FNR- mutant (NC983) in the pathogenic wild-type (WT) strain, ATCC14028s. Keywords: FNR, Salmonella, anaerobic, virulence
