Query: NC_017512:2087098 Neisseria meningitidis WUE 2594, complete genome
Lineage: Neisseria meningitidis; Neisseria; Neisseriaceae; Neisseriales; Proteobacteria; Bacteria
General Information: The second of two pathogenic Neisseria, this organism causes septicemia and is the leading cause of life-threatening meningitis (inflammation of the meninges, the membrane surrounding the brain and spinal cord) in children. This organism typically residies in the nasopharynx cavity but can invade the respiratory epthelial barrier, cross into the bloodstream and the blood brain barrier, and cause inflammation of the meninges. Pathogenicity factors include the surface proteins (porins and opacity proteins), and the type IV pilus (which is also found in Neisseria gonorrhoeae). This organism, like Neisseria gonorrhoeae, is naturally competent, and protein complexes at the cell surface recognize the uptake signal sequence in extracellular DNA, an 8mer that is found at high frequency in Neisseria chromosomal DNA.
Subject: NC_007413:1570000 Anabaena variabilis ATCC 29413, complete genome
Lineage: Anabaena variabilis; Anabaena; Nostocaceae; Nostocales; Cyanobacteria; Bacteria
General Information: These cyanobacteria are bluegreen algae that are capable of fixing carbon and nitrogen. They form long filaments and can be found worldwide in various aquatic environments as well as some terrestrial ones. These bacteria can form a variety of differentiated cell types, including spore-like cells (akinetes), small motile filaments (hormongia) and most importantly, heterocysts that are nitrogen-producing cells. The heterocyst produces multiple layers outside of its cell wall, shuts down photosystem II in order to inhibit oxygenic photosynthesis and ramps up metabolism in order to use up the oxygen present. Heterocysts donate fixed nitrogen compounds as amino acids to neighboring cells and in return receive a photosynthetically produced carbon source such as sucrose. These organisms produce toxic blooms in aquatic environments that are harmful or fatal to animals and humans due to the various cyanotoxins they produce. Anabaena variabilis is a filamentous heterocyst-forming cyanobacterium that fixes nitrogen and CO2 using the energy of sunlight via oxygen-evolving plant-type photosynthesis. In addition, this organism has been studied extensively for the production of hydrogen using solar energy.