Query: NC_010556:141374 Exiguobacterium sibiricum 255-15, complete genome
Lineage: Exiguobacterium sibiricum; Exiguobacterium; Bacillales Family XII; Bacillales; Firmicutes; Bacteria
General Information: This organism was isolated from a 2-3 million-year permafrost core in Siberia, Russia and can survive and grow rapidly at low temperatures. Analysis of long-term survival of psychrophilic organisms such as this one may aid understanding of the potential growth of organisms in astrobiology. Exiguobacterium sibiricum is a psychrotolerant organism able to grow at temperatures that range from -6 to 40 degrees C. This organism is also able to survive repeated freeze/thaw cycles which may contribute to its ability to survive in cold environments.
Subject: NC_009785:387910 Streptococcus gordonii str. Challis substr. CH1, complete genome
Lineage: Streptococcus gordonii; Streptococcus; Streptococcaceae; Lactobacillales; Firmicutes; Bacteria
General Information: Normal human oral flora. Most streptococci are facultative anaerobes, and some are obligate anaerobes. Serologic grouping is based on antigenic differences in cell wall carbohydrates, in cell wall pili-associated protein, and in the polysaccharide capsule in group B streptococci. Streptococcus gordonii is a commensal member of the human oral flora. It initiates the formation of biofilms on tooth surfaces known as dental plaque, which is strongly associated with the development of dental cavities (caries) and gum disease. It is a frequent causative agent of bacterial endocarditis (inflammation of the membrane lining the heart) which often occurs as a result of oral trauma, allowing S. gordonii to invade the bloodstream and colonize the heart.