Query: NC_011969:3657360 Bacillus cereus Q1 chromosome, complete genome
Lineage: Bacillus cereus; Bacillus; Bacillaceae; Bacillales; Firmicutes; Bacteria
General Information: Isolated from a deep-subsurface oil reservoir in the Daqing oil field in northeastern China. This strain is non-pathogenic, and has potential for industrial use. Bacillus cereus is a Gram-positive, spore-forming bacterium of the B.cereus group. It is closely related to Bacillus anthracis and Bacillus thuringiensis. Bacillus cereus is a ubiquitous soil organism and opportunistic human pathogen most commonly associated with food poisoning, causing diarrheic (late onset) or emetic (quick onset) outbreaks.
Subject: NC_004061:237205 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.