Project description:The Lucinidae is a large family of marine bivalves. They occur in diverse habitats from shallow-water seagrass sediments to deep-sea hydrothermal vents. All members of this family so far investigated host intracellular sulfur-oxidizing symbionts that belong to the Gammaproteobacteria. We recently discovered the capability for nitrogen fixation in draft genomes of the symbionts of Loripes lucinalis from the Bay of Fetovaia, Elba, Italy. With proteomics, we investigated whether the genes for nitrogen fixation are expressed by the symbionts.
Project description:This projiect aims to identify the proteome of the symbiotic gill, including the host and symbiotic bacteria proteins, and to reveal the metabolic interdependence among the tripartite holobiont which is based on mussel, methane-oxidizing endosymbiont and sulfur-oxidizing episymbiont.
Project description:Many sulfur-oxidizing prokaryotes oxidize sulfur compounds through a combination of initial extracytoplasmic and downstream cytoplasmic reactions. Facultative sulfur oxidizers adjust transcription to sulfur availability. While sulfur-oxidizing enzymes and transcriptional repressors have been extensively studied, sulfur import into the cytoplasm and how regulators sense external sulfur are poorly understood. Addressing this gap, we show that SoxT1A and SoxT1B, which resemble YeeE/YedE-family thiosulfate transporters and are encoded alongside sulfur oxidation and transcriptional regulation genes, fulfill these roles in the Alphaproteobacterium Hyphomicrobium denitrificans. RT-qPCR provided initial evidence that SoxT1A and SoxT1B from H. denitrificans may be intricate components of the oxidation pathway and/or involved in its transcriptional regulation. Here, we extend these analyses with genome-wide mRNA-Seq data for the reference strain, comparing transcription in the absence and presence of 2 mM thiosulfate
Project description:The purple sulfur bacterium Allochromatium vinosum DSM 180T is one of the best studied sulfur-oxidizing anoxygenic phototrophic bacteria and has been developed into a model organism for laboratory-based studies of oxidative sulfur metabolism. Here, we took advantage of the organism’s high metabolic versatility and performed whole-genome transcriptional profiling to investigate the response of A. vinosum cells upon exposure to sulfide, thiosulfate, elemental sulfur or sulfite as compared to photoorganoheterotrophic growth on malate. Differential expression (at least twofold) of 1149 genes was observed, corresponding to 30% of the A. vinosum genome. A total of 549 genes were identified for which relative transcription increased at least twofold during growth on one of the different sulfur sources while relative transcription of 599 genes decreased. A significant number of genes that were strongly induced have documented sulfur-metabolism-related functions. Among these are the dsr genes including dsrAB for dissimilatory sulfite reductase and the sgp genes for the proteins of the sulfur globule envelope thus confirming former results. In addition we were able to identify new genes encoding proteins with appropriate subcellular localization and properties to participate in oxidative dissimilatory sulfur metabolism. Two of these were chosen for inactivation and phenotypic analyses of the respective mutant strains. This approach verified the importance of the encoded proteins for the oxidation of sulfide and thereby also documented the suitability of comparative transcriptomics for the identification of new sulfur-related genes in anoxygenic phototrophic sulfur bacteria.
Project description:The purple sulfur bacterium Allochromatium vinosum DSM 180T is one of the best studied sulfur-oxidizing anoxygenic phototrophic bacteria and has been developed into a model organism for laboratory-based studies of oxidative sulfur metabolism. Here, we took advantage of the organism’s high metabolic versatility and performed whole-genome transcriptional profiling to investigate the response of A. vinosum cells upon exposure to sulfide, thiosulfate, elemental sulfur or sulfite as compared to photoorganoheterotrophic growth on malate. Differential expression (at least twofold) of 1149 genes was observed, corresponding to 30% of the A. vinosum genome. A total of 549 genes were identified for which relative transcription increased at least twofold during growth on one of the different sulfur sources while relative transcription of 599 genes decreased. A significant number of genes that were strongly induced have documented sulfur-metabolism-related functions. Among these are the dsr genes including dsrAB for dissimilatory sulfite reductase and the sgp genes for the proteins of the sulfur globule envelope thus confirming former results. In addition we were able to identify new genes encoding proteins with appropriate subcellular localization and properties to participate in oxidative dissimilatory sulfur metabolism. Two of these were chosen for inactivation and phenotypic analyses of the respective mutant strains. This approach verified the importance of the encoded proteins for the oxidation of sulfide and thereby also documented the suitability of comparative transcriptomics for the identification of new sulfur-related genes in anoxygenic phototrophic sulfur bacteria.
2013-07-29 | GSE44040 | GEO
Project description:Genomics of new thermophilic sulfur-oxidizing bacteria
Project description:The purple sulfur bacterium Allochromatium vinosum DSM 180T is one of the best studied sulfur-oxidizing anoxygenic phototrophic bacteria and has been developed into a model organism for laboratory-based studies of oxidative sulfur metabolism. Here, we took advantage of the organismM-bM-^@M-^Ys high metabolic versatility and performed whole-genome transcriptional profiling to investigate the response of A. vinosum cells upon exposure to sulfide, thiosulfate, elemental sulfur or sulfite as compared to photoorganoheterotrophic growth on malate. Differential expression (at least twofold) of 1149 genes was observed, corresponding to 30% of the A. vinosum genome. A total of 549 genes were identified for which relative transcription increased at least twofold during growth on one of the different sulfur sources while relative transcription of 599 genes decreased. A significant number of genes that were strongly induced have documented sulfur-metabolism-related functions. Among these are the dsr genes including dsrAB for dissimilatory sulfite reductase and the sgp genes for the proteins of the sulfur globule envelope thus confirming former results. In addition we were able to identify new genes encoding proteins with appropriate subcellular localization and properties to participate in oxidative dissimilatory sulfur metabolism. Two of these were chosen for inactivation and phenotypic analyses of the respective mutant strains. This approach verified the importance of the encoded proteins for the oxidation of sulfide and thereby also documented the suitability of comparative transcriptomics for the identification of new sulfur-related genes in anoxygenic phototrophic sulfur bacteria. In this study, the relative genomic expression profiles of A. vinosum DSM 180T growing photolithoautotrophically on different reduced sulfur compounds were determined in comparison to those of cells grown photoorganoheterothrophically on malate (RCV medium) at exactly the same light intensity. The malate-containing medium was supplied with 0.815 mM sulfate in order to satisfy the sulfur-requirement for biosynthesis of sulfur-containing cell constituents. Three independent photolithoautotrophic cultures each, grown on sulfide, thiosulfate or sulfite were harvested 1 h, 2 h or 7 h, respectively, after inoculation. When elemental sulfur was the substrate, four independent cultures were harvested 3 h after inoculation.
Project description:The purple sulfur bacterium Allochromatium vinosum DSM 180T is one of the best studied sulfur-oxidizing anoxygenic phototrophic bacteria and has been developed into a model organism for laboratory-based studies of oxidative sulfur metabolism. Here, we took advantage of the organismM-bM-^@M-^Ys high metabolic versatility and performed whole-genome transcriptional profiling to investigate the response of A. vinosum cells upon exposure to sulfide, thiosulfate, elemental sulfur or sulfite as compared to photoorganoheterotrophic growth on malate. Differential expression (at least twofold) of 1149 genes was observed, corresponding to 30% of the A. vinosum genome. A total of 549 genes were identified for which relative transcription increased at least twofold during growth on one of the different sulfur sources while relative transcription of 599 genes decreased. A significant number of genes that were strongly induced have documented sulfur-metabolism-related functions. Among these are the dsr genes including dsrAB for dissimilatory sulfite reductase and the sgp genes for the proteins of the sulfur globule envelope thus confirming former results. In addition we were able to identify new genes encoding proteins with appropriate subcellular localization and properties to participate in oxidative dissimilatory sulfur metabolism. Two of these were chosen for inactivation and phenotypic analyses of the respective mutant strains. This approach verified the importance of the encoded proteins for the oxidation of sulfide and thereby also documented the suitability of comparative transcriptomics for the identification of new sulfur-related genes in anoxygenic phototrophic sulfur bacteria. In this study, the relative genomic expression profiles of A. vinosum DSM 180T growing photolithoautotrophically on different reduced sulfur compounds were determined in comparison to those of cells grown photoorganoheterothrophically on malate (RCV medium) at exactly the same light intensity. The malate-containing medium was supplied with 0.815 mM sulfate in order to satisfy the sulfur-requirement for biosynthesis of sulfur-containing cell constituents. Three independent photolithoautotrophic cultures each, grown on sulfide, thiosulfate or sulfite were harvested 1 h, 2 h or 7 h, respectively, after inoculation. When elemental sulfur was the substrate, four independent cultures were harvested 3 h after inoculation.
Project description:Bathymodiolin mussels are a group of bivalves associated with deep-sea reducing habitats, such as hydrothermal vents and cold seeps. These mussels usually engage in an obligatory symbiosis with sulfur and/or methane oxidizing Gammaproteobacteria. In addition to these bacteria, Bathymodiolus heckerae that inhabit gas and oil seeps in Campeche Bay, the southern Gulf of Mexico, host bacteria phylogenetically with the Cycloclasticus genus. We recently discovered the capability for short-chain alkane degradation in draft genomes of symbiotic Cycloclasticus. With proteomics, we investigated whether the genes required for this process are expressed by the symbionts.
2016-12-05 | PXD005351 | Pride
Project description:Sulfur-oxidizing bacteria community structure in mangrove wetlands