For example, rhizobia living in root nodules of legumes provide nitrogen fixing activity for these plants.
[5] Certain plants establish a symbiotic relationship with bacteria, enabling them to produce nodules that facilitate the conversion of atmospheric nitrogen to ammonia.
In this connection, cytokinins have been found to play a role in the development of root fixing nodules.
Corals must therefore form a mutualistic relationship with nitrogen fixing organism, in this case the subject of this study, namely Symbiodinium.
[9] The problem is that these dinoflagellates are also nitrogen limited and must form a symbiotic relationship with another organism; here it is suggested to be diazotrophs.
[8] This particular study goes further to investigate the possibility that in addition to the named dinoflagellate and certain cyanobacteria, endosymbiotic algae and the coral contain enzymes enabling them to both undergo ammonium assimilation.
Due to the small size of the genome of most endosymbionts, they are unable to exist for any length of time outside of the host cell, thereby preventing a long-term symbiotic relationship.
There is a mutualistic relationship between legumes and rhizobial bacteria enabling the plants to survive in an otherwise nitrogen-poor soil environment.
In a study reported in Functional Ecology,[11] these scientists investigated whether such a mutualistic relationship conferred an evolutionary advantage to either plant or symbiont.
[12] Trichonympha is an endosymbiont that lives inside termites and also acts as a host to bacterial symbionts.
The termites, the gut protist Trichonympha, and the cellulase-producing bacteria are all involved in a 3-way obligate symbiotic mutualism.
If not treated carefully, this can lead to issues with the gastrointestinal tract because of an imbalance of bacteria in this microbiome.
Triatomine vectors have only one host and therefore must establish a relationship with bacteria to enable them to obtain the nutrients required to maintain themselves.