Project description:Oxidative Stress Protection and the Repair Response To Hydrogen Peroxide in the Hyperthermophilic Archaeon Pyrococcus furiosus Pyrococcus furiosus is a shallow marine, anaerobic archaeon that grows optimally at 100°C. Addition of H2O2 (0.5 mM) to a growing culture resulted in cessation of growth with a 2 hour lag before normal growth resumed. Whole genome transcriptional profiling revealed that the main response occurs within 30 min of peroxide addition, with the up-regulation of 62 open reading frames (ORFs), 36 of which are part of 10 potential operons. More than half of the up-regulated ORFs are of unknown function while some others encode proteins that are involved potentially in sequestering iron and sulfide, in DNA repair and in generating NADPH. This response is thought to involve primarily damage repair rather than protection, since cultures exposed to sub-toxic levels of H2O2 were not more resistant to the subsequent addition of H2O2 (0.5 – 5.0 mM). Consequently, there is little if any induced protective response to peroxide, rather, the organism maintains a constitutive protective mechanism involving high levels of oxidoreductase-type enzymes such as superoxide reductase, rubrerythrin and alkyl hydroperoxide reductase I. The related hyperthermophiles P. woesei and Thermococcus kodakaraensis were more sensitive to peroxide than P. furiosus, apparently due to the lack of several of its peroxide-responsive ORFs.
Project description:Experimentally mapped transcriptome structure of Pyrococcus furiosus DSM 3638 by hybridizing total RNA (including RNA species <200 nt) to genome-wide high-density tiling arrays (60 mer probes tiled every 16 nt).
Project description:Pyrococcus yayanosii CH1 is the first and only obligate piezophilic hyperthermophilic microorganism discovered so far, that extends the physical and chemical limits of life on Earth and strengthens the idea of the existence of a hyperthermophilic biosphere in the depth of our planet. It was isolated from the Ashadze hydrothermal vent at 4,100 m depth. Multi-omics analyses where performed in order to study the mechanisms implemented by the cell to face high hydrostatic pressure variations. In silico analyses showed that P. yayanosii genome is highly adapted to its harsh environment with precisely a loss of aromatic amino acid biosynthesis and the high constitutive expression of the energy metabolism compared to others non obligate piezophilic Pyrococus. Differential proteomics and transcriptomics analyses identified key hydrostatic pressure responsive genes involved in translation, chemotaxis, energy metabolism (hydrogenases and formate metabolism) and CRISPR-cas.
Project description:We designed an experimental setup to investigate the transcriptomic and proteomic responses of the hyperthermophilic archaeon Pyrococcus furiosus to heat and cold shock. P. furiosus is a model organism for studying microbial adaptation to extreme environments, including deep-sea hydrothermal vents with temperature gradients ranging from 1°C to 400°C. We aimed to simulate critical conditions where P. furiosus cannot grow and to examine the immediate response to thermal stress as well as the recovery process.
