High hydrostatic pressure adaptive strategies in an obligate piezophile Pyrococcus yayanosii and piezosensible Pyrococcus furiosus

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. Cells were grown at different hydrostatic pressures (20, 52 and 80 Mpa for P. yayanosii and 0.1 and 45 Mpa for P. furiosus) until they reached the middle of the exponential phase. Each culture was done 3 times independantly.