Nitrobacter winogradskyi

A Microbial Biorealm page on the genus Nitrobacter winogradskyi

Classification

Higher order taxa

Bacteria;Proteobacteria;Alphaproteobacteria;Rhizobiales;Bradyrhizobiaceae;Nitrobacter

Genus

Nitrobacter winogradskyi Nb-255

NCBI: Taxonomy

Description and significance

Nitrobacter winogradsky can be found living in many soils, natural stones as well as both fresh water and salt water. They have many differing rod shaped cells which divide through polar swelling. Along with having two membranes, it has flagella and contains an asymmetrical membrane system, carboxysomes along with intracellular inclusion bodies. It can grow in both aerobic and anarobic conditions with nitrate as its electron acceptor during anoxic conditions. Heterotrophic growth in this bacteria is not very efficient and all KREB cycle acids are present. It is important to sequence the genome of Nitrobacter winogradskyi to understand the relation between itself and other bacteria involved in the nitrogen cycle in order to improve nitrogen management.(1)

Genome structure

Nitrobacter winogradskyi has a circlular DNA chormosome with the length of 3,402,093 bp encoding 3,143 predicted proteins. The genome is make up of around 62% GC pairs. 2566 were assigned a role in catagories.(2)

Cell structure and metabolism

Nitrobacter winogradskyi are gram negative bacteria which play a key role in the nitrogen cycle by converting nitrite to nitrate. Nitrite is the end product of ammonium oxidation during the nitrifictation process of the nitrogen cycle. It derives its energy through nitrite oxidation and carbon dioxide fixation, which it can do simultaniously, thus acting as a chemolithoautotroph.(1) In the absence of nitrite it uses soley carbon sources and acts as a chemoorganoheterotroph. It uses nitrate as an electron acceptor producing nitrite, nitric oxide and nitrous oxide. When oxygen is present it oxidizes nitrite to nitrite and then further to nitrate. It is capabale of using nitric oxide adn a subrate to produce NADH.(2)

Ecology

It interacts with ammonium oxidizing bacteria which also plays a key role in the nitrogen cycle. Ammonium oxidizing bacteria inititaites nitrification, in which nitrite is the end product. Nitrobacter winogradskyi then proceeds to oxidize nitrite to nitrate.(1)

Pathology

There is no known virulence

Application to Biotechnology

As can be seen through current research done on Nitrobacter winogradskyi along with other nitrobacter, they allow for the removal of significant amounts of nitrogen from effluent wastewater through the use of biofilms.

Current Research

Current reseach has been done on the genome sequence of Nirtobacter winogradsky in oder to better understand its role in the nitrogen cycle. It was found that 10% of the genome codes for genes involved in transport and secretion. They hope that its genome will serve as a reference to study the mechanism which controls nitrite oxidation and its interaction with other processes.(3)

Current research is being done on how nitrofying bacteria such such as nitrobacter can be used for ammonium removal of waistwater effluents. In this study it was shown that using biofilms including nitrobacter winogradskyi could be a lead to a promising and inexpensive way of treating waistwater for bioremediation of effluents.(4)

Current reseach has demonstrated that extracellular polymeric substances(EPS) have been shown to play a key role in the formaiton of nitrofying biofilms. It was shown that when hetorotrophs isolates were cultured with Nitrobacter winogradskyi, significance biofilm growth was demonstrated(5)

References

(1)example: http://genome.jgi-psf.org/finished_microbes/nitwi/nitwi.home.html

(2)http://www.microbionet.com.au/nwinogradskyi.htm

(3)http://aem.asm.org/cgi/content/full/72/3/2050?view=long&pmid=16517654 Shawn R. Starkenburg,1 Patrick S. G. Chain,2,3 Luis A. Sayavedra-Soto,1 Loren Hauser,4 Miriam L. Land,4 Frank W. Larimer,4 Stephanie A. Malfatti,3 Martin G. Klotz,5 Peter J. Bottomley,1 Daniel J. Arp,1 and William J. Hickey6*.2006. " Genome Sequence of the Chemolithoautotrophic Nitrite-Oxidizing Bacterium Nitrobacter winogradskyi Nb-255."Applied and Environmental Microbiology, March 2006, p. 2050-2063, Vol. 72, No. 3 0099-2240/06/

(4)http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=Display&DB=pubmed Franco-Rivera A, Paniagua-Michel J, Zamora-Castro J.2007. "Characterization and performance of constructed nitrifying biofilms during nitrogen bioremediation of a wastewater effluent." J Ind Microbiol Biotechnol. 2007 Apr;34(4):279-87.

(5)http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=Display&DB=pubmed Tsuneda S, Park S, Hayashi H, Jung J, Hirata A.2001. "Enhancement of nitrifying biofilm formation using selected EPS produced by heterotrophic bacteria."Department of Chemical Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.2001;43(6):197-204

Edited by Marilyn Mendoz of Rachel Larsen and Kit Pogliano class