Lakhal Raja auteur aut IRD Auria Richard auteur aut IRD Davidson Sylvain auteur aut IRD Ollivier Bernard auteur aut IRD Durand M. C. auteur aut IRD Dolla A. auteur aut IRD Hamdi M. auteur aut IRD Combet-Blanc Yannick auteur aut IRD text journalArticle eng text/pdf born digital access A 2.3-L bioreactor was specially adapted to grow hyperthermophilic microorganisms under controlled conditions of temperature, pH, redox potential and dissolved O-2. Using this bioreactor regulated at 80A degrees C and pH 7.0, we demonstrated that Thermotoga maritima recovered its growth despite being exposed to oxygen for a short time (30 min with a maximum concentration of 23 mu M of dissolved oxygen). Under these conditions, we demonstrated that O-2 uptake rate, estimated at 73.6 mu moles O-2 min(-1) g proteins(-1) for dissolved oxygen, was optimal and constant, when dissolved oxygen was present in a range of 22-5 mu M. Transcription analyses revealed that during short oxygen exposure, T. maritima expressed genes coding for enzymes to deal with O-2 and reactive oxygen species (ROS) such as peroxides. Thus, genes encoding ROS-scavenging systems, alkyl hydroperoxide reductase (ahp), thioredoxin-dependent thiol peroxidase (bcp 2) and to a lesser extent neelaredoxin (nlr) and rubrerythrin (rbr), were found to be upregulated during oxygen exposure. The oxygen reductase FprA, homologous to the rubredoxin-oxygen oxidoreductase (ROO) found in Desulfovibrio species, is proposed as a primary consumer of O-2 in T. maritima. Moreover, the expression of frpA was shown to depend on the redox (Eh) level of the culture medium. specialized Thermotoga maritima Oxidative stress Oxygen 084 193 6 429-438 2011 0302-8933 https://www.documentation.ird.fr/hor/fdi:010053554 10.1007/s00203-011-0687-8 0302-8933 [F B010053554] https://www.documentation.ird.fr/hor/fdi:010053554 https://www.documentation.ird.fr/intranet/publi/2011/06/010053554.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2011-07-01 2017-08-23 fdi:010053554 fre