Query: NC_016776:3714642 Bacteroides fragilis 638R, complete genome
Lineage: Bacteroides fragilis; Bacteroides; Bacteroidaceae; Bacteroidales; Bacteroidetes; Bacteria
General Information: This group of microbes constitute the most abundant members of the intestinal microflora of mammals. Typically they are symbionts, but they can become opportunistic pathogens in the peritoneal (intra-abdominal) cavity. Breakdown of complex plant polysaccharides such as cellulose and hemicellulose and host-derived polysaccharides such as mucopolysaccharides is aided by the many enzymes these organisms produce. Although only a minor component of the human gut microflora, this organism is a major component of clinical specimens and is the most common anaerobe isolated.
Subject: NC_012560:603447 Azotobacter vinelandii DJ, complete genome
Lineage: Azotobacter vinelandii; Azotobacter; Pseudomonadaceae; Pseudomonadales; Proteobacteria; Bacteria
General Information: This organism was first isolated from the soil in Vineland, New Jersey, although it is found worldwide. It is a large obligate aerobe that has one of the highest respiratory rates of any organism. Azotobacter vinelandii also produces a number of unusual nitrogenases which allow it to fix atmospheric nitrogen to ammonia, a compound it can then use as a nitrogen source. It protects the oxygen-sensitive nitrogenase enzymes through its high respiratory rate, which sequesters the nitrogenase complexes in an anoxic environment. This organism has a number of unusual characteristics. Under extreme environmental conditions, the cell will produce a cyst that is resistant to dessication and is surrounded by two capsular polysaccharide layers. This organism produces two industrially important polysaccharides, poly-beta-hydroxybutyrate (PHB) and alginate. PHB is a thermoplastic biopolymer, and alginate is used in the food industry. Alginate is also used by the pathogen Pseudomonas aeruginosa to infect the lungs of cystic fibrosis patients.