Query: NC_011896:2240990 Mycobacterium leprae Br4923, complete genome
Lineage: Mycobacterium leprae; Mycobacterium; Mycobacteriaceae; Actinomycetales; Actinobacteria; Bacteria
General Information: This strain was isolated from a human skin biopsy in Brazil, and passaged in nude mice and armadillos. The bacterium is a close relative of M. tuberculosis. However, compared to the latter, the genome of M. leprae is smaller due to reductive genome evolution, with many important metabolic activities including siderophore production, part of the oxidative chain, most of the microaerophilic and anaerobic respiratory chains, and numerous catabolic systems and their regulatory circuits eliminated due to extensive recombination events between dispersed repetitive sequences. It is evident that this species has undergone massive genome reduction over time as a result of its parasitic nature, discarding more than half its genes and rendering it the most striking example of genome reduction in a microbial pathogen.
Subject: NC_012560:582011 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.