Bacteria; Proteobacteria; Alphaproteobacteria; Rhizobiales; Bradyrhizobiaceae; Nitrobacter; Nitrobacter hamburgensis
Description and significance
Nitrobacter hamburgensis, gram negative bacteria, was isolated from soil of the Old Botanic Garden in Hamburg and of a corn field in Yucatan. The main types of environments they inhabit are soil, building sandstone, and sewage sludge. Its cells are 0.5-0.8 x 1.2-2.0 m in size. They are pleomorphic; mostly pear-shaped and motile via one subpolar to lateral flagellum. Intracytoplasmic membranes appear as caps of flattened vesicles or membrane vesicles in the central region of the cell. The bacteria have an enzyme capable of oxidizing nitrite. This is why it is important to sequence the genome of N. hamburgensis.
There is one circular DNA chromosome and three circular DNA plasmids. The chromosome has 4,406,967 nucleotides. Plasmid 1 has 294,829 nucleotides, 2 has 188,318 nucleotides, and 3 has 121,408 nucleotides.
Cell structure and metabolism
N. hamburgensis gains energy from oxidation of nitrite to nitrate via the enzyme nitrite oxidoreductase (NOR). It grows best mixotrophically with a doubling time of 10 hours to 18 hours. Its growth rate under heterotrophic conditions is slower than under mixotrophic conditions, but higher than under lithoautotrophic conditions.