Biohydrogen production of obligate anaerobic archaeon Thermococcus onnurineus NA1 under oxic conditions via overexpression of frhAGB-encoding hydrogenase genes.

Via the overexpression of frhAGB genes, the obligate anaerobic archaeon T. onnurineus NA1 gained the ability to overcome the inhibitory effect of O2. This O2-tolerant property of the strain may provide another advantage to this hyperthermophilic archaeon as a platform for biofuel H2 production.