A Microbial Biorealm page on the genus Aquaspirillum bengal
Higher order taxa
Bacteria (domain); Protepbacteria (phylum); Betaprotepbacteria (class); Nitrosomonadales (order); Spirillacease (family); Aquaspirillum (genus).
Genus species (Aquaspirillum bengal)
Description and significance
Aquaspirillum bengal has helical shape and its deoxyribonucleic acid base composition is 51% mol guanine and cytosine.  It is Gram negative and chemo-organotrophic. It is also motile with the help of flagella.  It was isolated from a freshwater pond in West Bengal and it has a cell diameter of 0.9 to 1.2 μm. which are similar to those of Aquaspirillum serpens and A. putridiconchylium. In Aquaspirillum genus, this species is unique in having an unusually high temperature for optimal growth of 41 C, in forming water-soluble pigments from tyrosine and tryptophan, and in several other nutritional, biochemical, and serological characteristics.
The type strain of Aquaspirillum bengal was deposited with the American Type Culture Collection under the number 27641. One of specific characteristics of Aquaspirillum strains is in its ability to form pigments from aromatic amino acids. It's DNA base composition is: 
T," = 90.1 C; mol% G + C = 51
Cell and colony structure
Aquaspirillum bengal has cell diameter of 0.9 to 1.2 μm, cell length of 5.2 to 22.0 μm and wavelength of 4.6 to 8.1 pm. The diameter of helix is 1.7 to 2.3 μm and the colony diameter is 3 to 4 mm. Their swimming speed is between 40 to 52 μm/s. The colony color is light brown and the colony density is translucent. They contain intracellular granules, and also C16 : 1ω7c and/or iso-C15 : 0 2-OH as major fatty acids. 
This species has strict respiratory metabolism with oxygen as the terminal electron acceptor, and can not grow anaerobically with nitrate.Acetate, lactate, glutamate, succinate, and malate, can serve as oxidizable substrates, but not glucose. The organism is able to utilize some amino acids such as L-Alanine, L-Glutamate, L-Glutamine, and L-Aspartate. The best growth responses were obtained with alanine, pyruvate, lactate (nitrogen sources), glutamate, alanine, and asparagine (carbon sources). 
The organism prefers microaerophilic conditions for growth. It grows well in an air atmosphere and can grow at 0.5% NaCl but does not tolerate 1.0% NaCl. It shows no growth at 10 or 45 C. The optimum pH for this species is 7.2 but it can also tolerate a pH range from 6.0 to 8.4. 
There was not enough information on this part but they have some unique seriological characteristics. 
 Yoon, J. H., Kang, S. J., Park, S., Lee, S. Y. & Oh, T. K. (2007b). Reclassification of Aquaspirillum itersonii and Aquaspirillum peregrinum as Novispirillum itersonii gen. nov., comb. nov. and Insolitispirillum peregrinum gen. nov., comb. nov. Int J Syst Evol Microbiol 57, 2830–2835.
 Ranajit Kumar, A. K. Banerjee, J. H. Bowdre, L. J. McElroy, and N. R. Krieg Isolation, Characterization, and Taxonomy of Aquaspirillum bengal sp.nov. Int. J. Syst. Bacteriol. 1974 24: 453-458.
Edited by Shaghayegh Sabeti of Dr. Lisa R. Moore, University of Southern Maine, Department of Biological Sciences, http://www.usm.maine.edu/bio Category: Uncurated Pages