Project description:The acidotolerant sulfur reducer Desulfurella amilsii was isolated from sediments of Tinto River, an extremely acidic environment. Its ability to grow in a broad range of pH and to tolerate certain heavy metals offers potential for metal recovery processes. Here we report its high-quality draft genome sequence and compare it to the available genome sequences of other members of Desulfurellaceae family: D. acetivorans. D. multipotens, Hippea maritima. H. alviniae, H. medeae, and H. jasoniae. For most species, pairwise comparisons for average nucleotide identity (ANI) and in silico DNA-DNA hybridization (DDH) revealed ANI values from 67.5 to 80% and DDH values from 12.9 to 24.2%. D. acetivorans and D. multipotens, however, surpassed the estimated thresholds of species definition for both DDH (98.6%) and ANI (88.1%). Therefore, they should be merged to a single species. Comparative analysis of Desulfurellaceae genomes revealed different gene content for sulfur respiration between Desulfurella and Hippea species. Sulfur reductase is only encoded in D. amilsii, in which it is suggested to play a role in sulfur respiration, especially at low pH. Polysulfide reductase is only encoded in Hippea species; it is likely that this genus uses polysulfide as electron acceptor. Genes encoding thiosulfate reductase are present in all the genomes, but dissimilatory sulfite reductase is only present in Desulfurella species. Thus, thiosulfate respiration via sulfite is only likely in this genus. Although sulfur disproportionation occurs in Desulfurella species, the molecular mechanism behind this process is not yet understood, hampering a genome prediction. The metabolism of acetate in Desulfurella species can occur via the acetyl-CoA synthetase or via acetate kinase in combination with phosphate acetyltransferase, while in Hippea species, it might occur via the acetate kinase. Large differences in gene sets involved in resistance to acidic conditions were not detected among the genomes. Therefore, the regulation of those genes, or a mechanism not yet known, might be responsible for the unique ability of D. amilsii. This is the first report on comparative genomics of sulfur-reducing bacteria, which is valuable to give insight into this poorly understood metabolism, but of great potential for biotechnological purposes and of environmental significance.
Project description:Purpose: To identify gene expression patterns in ex vivo isolated human Tr1 cells. Method: RNA sequencing of total mRNA. Results: Differential gene expression of Tr1 and non-Tr1 CD4+ T memory cells. Conclusions: ex vivo type 1 regulatory T cells have a distinct gene expression profile compared to non-Tr1 CD4+ T cell memory cells.
Project description:Desulfurella amilsii is an acidotolerant sulfur-reducing bacterium isolated from sediments of an acidic river. It can grow in a broad range of pH and can obtain energy via respiring elemental sulfur or thiosulfate, as well as by disproportionating elemental sulfur. Its genome encodes the enzyme sulfur reductase, and several rhodanese-like proteins, possibly playing a role in sulfur respiration and disproportionation. Thiosulfate reductase and dissimilatory sulfite reductase are encoded and might play a role during the respiration of thiosulfate. The involvement of these enzymes in the reductive routes of sulfur metabolism is not yet clearly understood. Desulfurella amilsii was used in this study to combine strategies for sulfur metabolism research on the protein level to shed some light on the pathways involved in the metabolism of this microorganism.