Thermoanaerobacter kivui (formerly Acetogenium kivui) is a thermophilic, anaerobic, nonspore-forming species of bacteria.
T. kivui was originally isolated from Lake Kivu in Africa. The growth range for the organism is 50 to 72ðC at pH 5.3-7.3, with optimal growth conditions at 66ðC and pH 6.4. Although the organism stains Gram-negative, it shows a Gram-positive cell structure. The original genus Acetogenium was named because this organism principally produces acetic acid from substrates. T. kivui was originally named Acetogenium kivui, which was the only species within a new genus. However, further 16S ribosomal RNA studies put this bacterium into genus Thermoanaerobacter and the previous genus was no longer necessary.
T. kivui has been shown (with a technical readiness level of 4), to produce acetate with an input of H<sub>2</sub> and CO<sub>2</sub>. This process could be used as the initial stage in an alternative food source production system.