Query: NC_014219:25845 Bacillus selenitireducens MLS10 chromosome, complete genome
Lineage: Bacillus selenitireducens; Bacillus; Bacillaceae; Bacillales; Firmicutes; Bacteria
General Information: Isolation: Anoxic muds of Mono Lake California; Country: USA; Temp: Mesophile; Habitat: Fresh water. Bacillus selenitireducens MLS-10 was isolated from alkaline, hypersaline, arsenic-rich mud from Mono Lake, California. This organism can reduce arsenate, selenate, and selenite, making it a potential bioremediation agent. Bacillus selenitireducens produces intracellular and extracellular granules of elemental selenium when grown on selenite. The respiratory arsenate reductase has been purified, and is able to function at high pH and alkalinity.
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.