Combinatorial Chemistry and High Throughput Screening, 2025 (SCI-Expanded)
Background: Thermotoga maritima is an anaerobic hyperthermophilic eubacterium isolated from geothermally heated maritime surfaces. It can grow at temperatures up to 80 degrees Celsius. Methods: A 2.3-L bioreactor was specifically designed to cultivate hyperthermophilic bacteria under carefully regulated pH, redox potential, temperature, and dissolved O2. Results: Using this bioreactor, which was adjusted at 80°C and pH 7.0, it was found that Thermotoga maritima demonstrated continued growth even after being exposed to oxygen for an extended period. Transcription studies revealed that following prolonged oxygen exposure, the genes encoding ROS-scavenging systems, alkyl hydroperoxide reductase (ahp), thioredoxin-dependent thiol peroxidase (bcp 2), and, to a lesser extent, neelaredoxin (nlr), were upregulated/overexpressed. When oxygen was available, the metabolism of glucose was diverted to make lactate rather than acetate. Conclusion: Based on the O/R ratio of 1.0 in anaerobiosis and 1.67 in the presence of O2, we may conclude that Thermotoga maritima is capable of semi-oxidative metabolism.