Project description:Roothans et al., analyzed heterotrophic denitrification processes that can be an important source of nitrous oxide. We employed planktonic nitrification-inhibited denitrifying enrichment cultures under alternating oxic-anoxic conditions. The dynamic conditions resulted in a general presence of the denitrifying enzymes. Overall, we show that aerobic denitrification should not be neglected as an ecologically relevant process. Contact author: m.laureni@tudelft.nl
Project description:Beller, H. R., T. E. Letain, A. Chakicherla, S. R. Kane, T. C. Legler, and M. A. Coleman. 2006. Whole-genome transcriptional analysis of chemolithoautotrophic thiosulfate oxidation by Thiobacillus denitrificans under aerobic vs. denitrifying conditions. Journal of Bacteriology 188:7005-7015. Thiobacillus denitrificans is one of the few known obligate chemolithoautotrophic bacteria capable of energetically coupling thiosulfate oxidation to denitrification as well as aerobic respiration. As very little is known about the differential expression of genes associated with key chemolithoautotrophic functions (such as sulfur-compound oxidation and CO2 fixation) under aerobic versus denitrifying conditions, we conducted whole-genome, cDNA microarray studies to explore this topic systematically. The microarrays identified 277 genes (approximately ten percent of the genome) as differentially expressed using Robust Multi-array Average statistical analysis and a 2-fold cutoff. Genes upregulated (ca. 6- to 150-fold) under aerobic conditions included a cluster of genes associated with iron acquisition (e.g., siderophore-related genes), a cluster of cytochrome cbb3 oxidase genes, cbbL and cbbS (encoding the large and small subunits of form I ribulose 1,5-bisphosphate carboxylase/oxygenase, or RubisCO), and multiple molecular chaperone genes. Genes upregulated (ca. 4- to 95-fold) under denitrifying conditions included nar, nir, and nor genes (associated respectively with nitrate reductase, nitrite reductase, and nitric oxide reductase, which catalyze successive steps of denitrification), cbbM (encoding form II RubisCO), and genes involved with sulfur-compound oxidation (including two physically separated but highly similar copies of sulfide:quinone oxidoreductase and of dsrC, associated with dissimilatory sulfite reductase). Among genes associated with denitrification, relative expression levels (i.e., degree of upregulation with nitrate) tended to decrease in the order nar > nir > nor > nos. Reverse transcription, quantitative PCR analysis was used to validate these trends. Keywords: bacterial metabolism
2006-10-06 | GSE5256 | GEO
Project description:simultaneous nitrification and autotrophic denitrification
Project description:Sulfur autotrophic denitrification reactor Raw sequence reads
| PRJNA1117246 | ENA
Project description:Investigation of the Transformation Performance from Heterotrophic Denitrification, Mixotrophic Denitrification, and Autotrophic Denitrification to Anammox of a UASB Reactor
| PRJNA1046248 | ENA
Project description:Microbial community of aerobic denitrification reactor
| PRJNA594167 | ENA
Project description:microbial community of an aerobic denitrification reactor
Project description:The effect of respiration (aerobic cultivation in the presence of heme and vitamin K2) was compared with unsupplemented aerobic cultivation with Lactobacillus plantarum. Two-condition experiment, aerobic vs respiring cells. Biological replicates: 3 aerobic cultures, 3 respiring cultures, independently grown and harvested. One replicate per array. Respiring cultures are called reactor 1-3; Aerobic cultures are called reactor 4-6 In the subsequent analysis data from reactor 4 were not used. There was likely a mistake made during quenching. This was concluded as new labeling/hybridisation gave same (bad) results (128a); slide 128b was dye-swap.
Project description:Polyphosphate accumulating organisms are responsible for enhanced biological phosphate removal from wastewater, where they grow embedded in a matrix of extracellular polymeric substances. Little is known about the composition and dynamics of those proteins and their production by the different microorganisms. Tomás-Martínez et al., (2022) studied the turnover of proteins and polysaccharides in extracellular polymeric fractions of an enrichment culture of polyphosphate accumulating organisms using an anaerobic-aerobic sequencing batch reactor simulating EBPR conditions. Finally, the carbon source was switched to 13C-labelled acetate to study the protein turnover. Samples were collected at the end of each aerobic phase.