Cenarchaeum symbiosum
A Microbial Biorealm page on the genus Cenarchaeum symbiosum
Classification
Domain: Archaea; Phylum: Thaumarchaeota; Class: incertae sedis; Order: Cenarchaeales; family:Cenarchaeaceae; genus: Cenarchaeum; species:Cenarchaeum symbiosum aka Candidatus Cenarchaeum
Description and significance
Cenarchaeum symbiosum is a marine archaeon that inhabits the tissues of temperate water sponges such as Axinella Mexicana. It was first discovered off the cost of Santa Barbara, California. It's discovery represents the first symbiosis involving Crenarchaeota. C. symbiosum grows well at temperatures around 10 degrees Celsius, much lower than many other Crenarchaeota. C. symbiosum has not yet been cultivated in lab, but can be harvested in high amounts from it's host's tissues with a microbial mass around 65%.
Genome structure
The genome of c. symbiosum is 2.05 million bp in length and is a single circular chromosome with about 2,066 genes. It shares many core genomic and metabolic features with other planktonic relatives. Ammonia oxidation genes were also found in the genome of C. symbiosum.
Cell structure, metabolism & life cycle
The cell structure of c. symbiosum is bacillus shaped. Genetic analysis of this archaeon shows that it uses an incomplete TCA cycle, and also the EMP pathway. A pentose phosphate shunt was also discovered in the genetic analysis. The life cycle of c. symbiosum is active in association with the host sponge.
Ecology (including pathogenesis)
C. symbiosum is a psychrophilic archaeon and lives in temperatures ranging from 8 to 18 degrees Celsius. It lives symbiotically with sponge species about 10-20 meters in the depth of the Pacific Ocean near California.
Interesting feature
Cenarchaeum symbiosum was the first discovery of a psychrophillic Crenarchaeote that had a symbiotic relationship with another organism.