Project description:The leaf transcriptome of the nickel hyperaccumulator specie Noccaea caerulescens subsp. fimiensis living on serpentine soils were compared to the closely related non-nickel-accumulators Noccaea caerulescens "Viviez" growing on a zinc mining site and Noccaea montana living on serpentine soil, to identity differentially expressed genes potentially involved in Ni hyperaccumulation.
Project description:Thermoacidophilic archaea are found in heavy metal-rich environments and, in some cases, these microorganisms are causative agents of metal mobilization through cellular processes related to their bioenergetics. Given the nature of their habitats, these microorganisms must deal with the potentially toxic effect of heavy metals. Here, we show that two thermoacidophilic Metallosphaera species with nearly identical (99.99%) genomes differed significantly in their sensitivity and reactivity to uranium. M. prunae, isolated from a smoldering heap on a uranium mine in Thuringen, Germany, could be viewed as a M-bM-^@M-^\spontaneous mutantM-bM-^@M-^] of M. sedula, an isolate from Pisciarelli solfatara near Naples, Italy. M. prunae tolerated U3O8 and U(VI) to a much greater extent than M. sedula. Within 15 minutes following exposure to M-bM-^@M-^\U(VI) shockM-bM-^@M-^], M. sedula, and not M. prunae, exhibited transcriptomic features associated with severe stress response. Furthermore, within 15 minutes post-U(VI) shock, M. prunae, and not M. sedula, showed evidence of substantial degradation of cellular RNA. This suggested that transcriptional and translational processes were aborted as a dynamic mechanism for resisting U toxicity; by 60 minutes post-U(VI) shock, RNA integrity in M. prunae recovered, and known modes for heavy metal resistance were activated. In addition, M. sedula rapidly oxidized solid U3O8 to soluble U(VI) for bioenergetic purposes, a chemolithoautotrophic feature not previously reported. M. prunae, however, did not solubilize solid U3O8 to any significant extent, thereby not exacerbating U(VI) toxicity. These results point to uranium extremophily as an adaptive, rather than intrinsic, feature for Metallosphaera species, driven by environmental factors. The study comprises 9 Samples, described in detail below. MprAU_MseAU: Transcriptional analysis of the response of Metallosphaera prunae (Mpr) and Metallosphaera sedula(Mse) to chemolithoautotrophic conditions (0.1 wt% Uranium octaoxide with CO2 supplementation in headspace). This experiment was done to identify the key terminal oxidases which responded to a Uranium oxide while doing inter-species comparison between Mpr and Mse. Transcriptional response of the terminal oxidase clusters proved that certain key genes play a role in the vastly different physiologies of these two species. MprN_MprU60: Transcriptional analysis of the response of Metallosphaera prunae (Mpr) to 60 min of Uranium shock. This experiment was done to analyze the differential transcription of Mpr cells challenged with 1 mM uranyl acetate shock (U shock) compared to normal growth. The Uranium cultures were harvested 60 min after the shock. MprN_MseN: Differential transcription of Metallosphaera species under normal growth conditions. This experiment was done to analyze the differential transcription of Mpr cells compared with Mse cells at mid log phase. MprN_MprU3h: Transcriptional response of Metallosphaera prunae (Mpr) to 3h of Uranium shock compared to normal growth. This experiment was done to analyze the differential transcription of Mpr cells challenged with 1 mM uranyl acetate shock (U shock) . The Uranium cultures were harvested 3 h after the shock. MseN_MseU15: Transcriptional response of Metallosphaera sedula (Mse) to 15 min of Uranium shock. This experiment was done to analyze the differential transcription of Mse cells challenged with 1 mM uranyl acetate shock (U shock) compared to normal growth. The Uranium cultures were harvested 15 min after the shock. MseN_MseU60: Transcriptional response of Metallosphaera sedula to 60 min of Uranium shock. Mse cells were grown upto mid log phase after which the cells were subjected to U shock and harvested 60 min later. Biological repeats were done for both experimental conditions. MseN_MseU3h: Transcriptional response of Metallosphaera sedula (Mse) to 3h of Uranium shock compared to normal growth. This experiment was done to analyze the differential transcription of Mse cells challenged with 1 mM uranyl acetate shock (U shock) . The Uranium cultures were harvested 3 h after the shock. MseU15_MseU60: Transcriptional response of Metallosphaera sedula to 15 min of Uranium shock compared with 60 min of Uranium shock. This experiment was done to analyze the differential transcription of Mse cells challenged with 1 mM uranyl acetate shock (U shock) . The Uranium cultures were harvested 15 min and 60 min after the shock. MprU3h_MseU3h: Differential transcription of Metallosphaera cells under Uranium shock. This experiment was done to analyze the differential transcription of Metallosphaera sedula (Mse) and Metallosphaera prunae (Mpr) challenged with 1 mM uranyl acetate.
Project description:Investigation of global gene expression changes in Saccharomyces cerevisiae strain NRRL Y-12632 (ATCC® 18824) grown in media made with asbestos mine tailings-laden water compared to the control grown in media made with double distilled water
Project description:Three strains of the Aspergillus versicolor complex were isolated from a salty marsh at a former uranium mining site in Thuringia, Germany. The strains from a metal-rich environment were not only highly salt tolerant (up to 20% NaCl), but at the same time could sustain elevated Cs and Sr (both up to 100 mM) concentrations as well as other (heavy) metals present in the environment. During growth experiments when screening for differential cell morphology, the occurrence of guttation droplets was observed, specifically when elevated Sr concentrations of 25 mM were present in the media. To analyze the potential of metal tolerance being promoted by these excretions, proteomics and metabolomics of guttation droplets were performed. Indeed, proteins involved in up-regulated metabolic activities as well as in stress responses were identified. The metabolome verified the presence of amino sugars, glucose homeostasis regulating substance, (S)-abscisic acid and bioactive alkaloids, flavones and quinones.