Query: NC_009718:799431 Fervidobacterium nodosum Rt17-B1, complete genome
Lineage: Fervidobacterium nodosum; Fervidobacterium; Thermotogaceae; Thermotogales; Thermotogae; Bacteria
General Information: Fervidobacterium nodosum is a thermophilic, Gram-negative, motile, non-sporulating, glycolytic, obligately anaerobic rod that exists singly, in pairs or in chains. Fervidobacterium nodosum was isolated from a hot spring in New Zealand. Its optimal growth temperature is 65 to 70 degrees Celsius. The cellular morphology of this organism, a member of the Thermotogales, is characterized by a terminal spherical extension of the cell envelope.
Subject: NC_004061:540354 Buchnera aphidicola str. Sg (Schizaphis graminum), complete genome
Lineage: Buchnera aphidicola; Buchnera; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria
General Information: This strain is the symbiont of the aphid Schizaphis graminum and contains a large circular chromosome. Aphid endosymbiont. Almost all aphids contain maternally transmitted bacteriocyte cells, which themselves contain bacteria called Buchnera. The aphids live on a restricted diet (plant sap), rich in carbohydrates, but poor in nitrogenous or other essential compounds. It is believed that the Buchnera provide the essential nutrients the host lacks. Besides a nutritional co-dependence, due to a co-existence of millions of years, Buchnera have lost the ability to produce cell surface components such as lipopolysaccharides. This makes for an obligate endosymbiont relationship between host and Buchnera. Buchnera are prokaryotic cells which belong to the gamma-Proteobacteria, closely related to the Enterobacteriaceae family. Phylogenetic studies using 16S rRNA indicate that the symbiotic relationship was established around 200-250 million years ago. Since Buchnera are closely related to Escherichia coli and Haemophilus influenzae, comparative genomic studies can shed light on the evolutionary mechanisms of intracellular endosymbiosis as well as the different underlying molecular basis between organisms with parasitic behavior and symbionts.