''Blattabacterium'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of obligate mutualistic

endosymbiont An ''endosymbiont'' or ''endobiont'' is any organism that lives within the body or cells of another organism most often, though not always, in a mutualistic relationship. (The term endosymbiosis is from the Greek: ἔνδον ''endon'' "within ...

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...

that are believed to inhabit all species of

cockroach Cockroaches (or roaches) are a Paraphyly, paraphyletic group of insects belonging to Blattodea, containing all members of the group except termites. About 30 cockroach species out of 4,600 are associated with human habitats. Some species are we ...

studied to date, with the exception of the genus '' Nocticola''. The genus' presence in the termite ''

Mastotermes darwiniensis ''Mastotermes darwiniensis'', common names giant northern termite and Darwin termite, is a termite species found only in northern Australia. It is the most primitive extant termite species. Evolutionary significance This species shows uncanny s ...

'' led to speculation, later confirmed, that termites and cockroaches are evolutionarily linked.

Diversity

''B. cuenoti'' was traditionally considered the only species in the genus ''Blattabacterium'', which is in turn the only genus in the family Blattabacteriaceae. However, three new species have been described hosted by different species of cockroaches in the genus ''

Cryptocercus ''Cryptocercus'' is a genus of Dictyoptera (cockroaches and allies) and the sole member of its own family Cryptocercidae. Species are known as wood roaches or brown-hooded cockroaches. These roaches are subsocial, their young requiring considerab ...

'': * ''Blattabacterium relictus'' in ''

Cryptocercus relictus ''Cryptocercus'' is a genus of Dictyoptera (cockroaches and allies) and the sole member of its own family Cryptocercidae. Species are known as wood roaches or brown-hooded cockroaches. These roaches are subsocial, their young requiring consider ...

'' * ''B. clevelandi'' in '' C. clevelandi'', and * ''B. punctulatus'' in '' C. darwini'', '' C. garciai'', '' C. punctulatus'' and '' C. wrighti''. The ancient (~150 My) genus retains throughout a core set of metabolic genes. According to the GTDB, the many strains of the genus have nevertheless diverged enough at the sequence level to define around 40 "species" out of ''B. cuenoti'' alone. In addition, newer genera have been found sufficiently closely related to the genus to warrant assignment to the same family by GTDB: Ca. "

Karelsulcia "''Candidatus'' Karelsulcia muelleri" is an aerobic organism, aerobic, Gram-negative bacteria, gram-negative, Bacillus (shape), bacillus bacterium that is a part of the phylum Bacteroidota. "''Ca.'' K. muelleri" is an obligate and mutualism (bi ...

", Ca. " Uzinura", Ca. " Walczuchella", all symbionts of insects.

Function

Blattabacterium lives inside the fat cells of the fat bodies (tissues in the abdominal cavity that store fat) of its insect hosts. It serves a vital role in nitrogen recycling, which is important in insects that mainly live on plant material such as wood, which are poor in nitrogen. In insects, uric acid is a waste product of protein metabolism. After breakdown of uric acid by the host (and its other microbial flora, such as gut bacteria and fungi) into urea and/or ammonia, blattabacterium recycles nitrogen by converting these products into glutamate, and using other raw materials from the host, is able to synthesize all of the essential amino acids and several vitamins. It appears to be transmitted to succeeding generations of the host by infection of the mother's eggs prior to their fertilization.

Diversity

Function

References

Further reading