Query: NC_016894:3329562 Acetobacterium woodii DSM 1030 chromosome, complete genome
Lineage: Acetobacterium woodii; Acetobacterium; Eubacteriaceae; Clostridiales; Firmicutes; Bacteria
General Information: Acetobacterium woodii is a Gram positive, motile, strict anaerobic, acetogenic bacterium, that relies on Na+ as coupling ion in bioenergetic reactions. The organism can use a wide range of substrates, such as sugars, alcohols, methoxylated aromatic acids or C1 compounds. Electrons derived from these electron donors are used in the Wood-Ljungdahl-pathway where the organism fixes CO2 and produces acetate. The pathway of CO2-fixation is coupled to energy conservation via a chemiosmotic mechanism, one enzyme that seems to be involved is the Rnf complex. The produced Na+ gradient can be used to drive ATP-synthesis or flagella rotation. The ATP synthase is a member of the F1FO class of enzymes and has an unusual hybrid rotor. Can use alternative electron acceptors like the lignin degradation product caffeate.
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.