Cenarchaeum symbiosum

Besides sponges and algae, enzymes were also isolated from marine organisms and microorganisms. For example, polymerases and proteases from marine Vibrio sp. [352], marine bacterium such as Alcaligenes faecalis [353], and from archaeons, such as the psychrophilic Cenarchaeum symbiosum [354], and the hyperthermophile archaeons Pyrococcus furiosus [355], Sulfolobus solfataricus [356], and Aeropyrum pernix [357] transferases from marine bacterium such as Vibrio vulnificus... 

The only cultivated AOA, Nitrospumilus maritimus, depends on CO2 as its only carbon source and the presence of even low levels of organic carbon were inhibitory to growth. The pathway of CO2 fixation is, however, unknown. Hyperthermophilic Crenarchaeota generally utilize a 3-hydroxypropionate pathway or a reductive TCA cycle for autotrophic carbon fixation. Another cultivated marine Crenarchaeota strain, Cenarchaeum symbiosum, a sponge symbiont, appears to use the 3-hydroxypropionate pathway. It cannot be concluded on this basis which pathway is used by the AOA, but it very likely that is not the Calvin cycle. N. maritimus had a minimal generation time of 21 h, longer but roughly on the same scale as AOB. 

HaUam, S. J., Konstantinidis, K. T., et al. (2006b). Genomic analysis of the uncultivated marine crenarchaeote Cenarchaeum symbiosum. Proc. Natl. Acad. Sci. USA 103, 18296-18301. 

Schleper, C., DeLong, E. P., et al. (1998). Genomic analysis reveals chromosomal variation in natural populations of the uncultured psychrophilic Archaeon Cenarchaeum symbiosum. J. Bacterial. 180, 5003-5009. 

---