Higher order taxa
Cellular organisms; Bacteria; Proteobacteria; Alphaproteobacteria; Sphingomonadales; Erythrobacteraceae; Erythrobacter.
Description and significance
The Erythrobacter litoralis is gram negative bacteria, and it is halotolerant aerobic anoxygenic phototrophs marine bacteria. This species is found in the nutrient rich coastal salt seawater. Erythrobacter litoralis can be found at the Sargasso Sea. These bacteria are well distributed in the euphotic zone. Erythrobacter litoralis can only grow under aerobic conditions. Like all of other species in the Erythrobacter genus, the Erythrobacter litoralis species also has no poreforming.(1,2)
Erythrobacter litoralis contains bacteriochlorophyll a and large amount of Carotenoids. The bacteriochlorophyll a is found in the harvesting system of Erythrobacter litoralis harvesting system. The presence of the bacteriochlorophyll a, however, does not give the Erythrobacter litoralis the ability of growing phototrophically under anaerobic conditions. The carotenoids display the smooth red orange color of this species. There is not sure whether the species Erythrobacter litoralis have any motility. Yet the Erythrobacter litoralis strain HTCC 25 has flagella and pili for motility.(1)
Erythrobacter litoralis is important in recycling of the inorganic and the organic matters, in reducing the toxic Tellurite, and in the studying of the LOV-histidine Kinase system. Therefore, it is important to sequence the genome of these bacteria. Because of the Erythrobacter litoralis sharing the same ability of being able to reduce the Tellurite with Erythromicrobium, the sequence genome of Erythrobacter litoralis can help reveal the relationship between the two microbes. Also the sequenced genome may explain the rise of the aerobic phototrophic bacteria and the places of those bacteria in the evolution scale. The study of the genome can help clarify whether gene transfer between micorbes was the factor for the rise of aerobic anoxygenic phototrophs.(2)
The Erythrobacter litoralis is an α-4 subclass of the class Proteobacteria. Erythrobacter litoralis has only Light Harvesting Complex 1(LH1) which absorbs the light with 871 nm wavelenghth, and there is no LH2 in these bacteria. These Erythrobacter litoralis can resist antibiotics such as Nalidixic acid, Polymyxin B, and Streptomycin. However, Erythrobacter litoralis can not resist Chloramphenicol, erythromycin, Penicillin, tetracycline.(4,2)
Cell structure and metabolism
Erythrobacter litoralis is a gram negative cell with no poreforming on its outer membrane. In general, Erythrobacter litoralis has no motility, yet the study of the strain HCCT2594 shows the motility of the bacteria. The appearance of this species includes the rod shape and the chain of up to 10 individual bacteria. In the strain HCCT2594, the bacteria's outer appearance also has pili and the flagella.(1)
Erythrobacter litoralis has the bacteriochlorophyll a and carotenoids, which are responsible for the smooth red and orange of the bacteria. Erythrobacter litoralis has 20 different carotenoids. However, Erythrobacter litoralis do not have the carotenoids Adonixanthin and 2,3,2',3'-tetrahydroxy-β,β-carotene-4-one. Like all of other species of the genus Erythrobacter, the Erythrobacter litoralis has Zeaxanthin as major a carotenoid. Carotenoids bacteriorubixanthinal and erythroxanthin sulfate display a reddish color in this species.(2)
The Erythrobacter litoralis has light harvesting system, reaction center, developed photosynthetis membrane, the photosynthetic electron transfer system including quinone, cytochrome composition, and the system that transfers of excitation energy from carotenoids to bacteriochlorophyll a.(2)
Oxygen is the major requirement for this aerobic bacteria's metabolism. Although there is bacteriochlorophyll a in the cell, the Erythrobacter litoralis can not survive without the oxygen as electron acceptor. These bacteria can reduce the organic matters as energy sources and use inorganic matters as electron donors.(1)
When the organic matter becomes scare, Erythrobacter litoralis will switch to the inorganic sources such as the sulfur compounds. Erythrobacter litoralis will perform aerobic anoxygenic phototroph. The sulfur compounds will be reduced with the help of the harvested sun light energy and the oxygen as the electron acceptor.(2)
Erythrobacter litoralis can be grown on organic carbon such as the Acetate, Butyrate, glucose, and Pyruvate. Those organic carbons are used as the simple carbon sources. It is possible that this species can also use the glutamate and Leucine as carbon sources. The Erythrobacter Litoralis can also use the Ammonium, Urea, Amino Acids as nitrogen sources. However, Erythrobacter Litoralis can not use the Nitrate. The inability of using Nitrate as nitrogen source is a common theme for the marine heterotrophic prokaryotes whose the nitrogen sources are dissolved organic matters. The Erythrobacter Litoralis can not have the diazotrophic growth either.(4)
Of all the erythrobacter litoralis, only the strain HTCC2594's genome is completely sequenced. Here, the HCCT2594's genome reveals the length of 3,052,398 nucleotides containing 3056 genes. The genome encodes for 3011 proteins and 45 structural RNAs. There is about 63.1 % of the GC content in the HCCT2594's genome. There are about 15 proteins for the carbohydrate metabolism, 9 proteins for the lipid metabolism, 16 proteins for the amino acid metabolism, and many more proteins for other functions.(1)
The Erythrobacter Litoralis lives in environments with sufficient sun light and adequate amount of oxygen. Oxygen is needed for the species' metabolisms. Euphotic zones, where there are at least 1 % of the sun light available, are places that Erythrobacter Litoralis can mostly be found . Although the first Aerobic phototrophic bacterium was discovered in Japan by T. Shiba, the Erythrobacteria genus can be found well distributed around the world. The Erythrobacter Litoralis species can be seen in oceanic coastal lines or places that have rich nutrients and adequate amount of sun light. The Erythrobacter Litoralis HCCT2594 was discovered at Sargasso Sea at a depth of 10 meters.(4)(1)
There is no reported disease caused by the Erythrobacter Litoralis.(1)
Although the Erythrobacter Litoralis is not a pathogen, the species shares the same LOV- histidine kinase system with Brucella, which is a vicious pathogen.(6)
Because of its ability of reducing the toxic Tellurite, Erythrobacter Litoralis is useful in the process of cleaning up the Tellurite Oxides. Tellurite compounds are toxic to other bacteria and other organisms including the human. The Tellurite compounds are reduced to give the insoluble crystal metal Tellurium. Large amount of the crystal metal Tellurium will be accumulated in the Erythrobacter Litoralis after the reduction. The Erythrobacter Litoralis can store the metal Tellurium up to 30% of its cell’s volume. This gives the Erythrobacter Litoralis a recognition as the potential bioremediation.(5,2)
The storage of the Tellurium metal in the Erythrobacter Litoralis cell can be harvested for pure Tellurim metal. Erythrobacter Litoralis, here, is used to extract the Tellurium metal from the Tellurite compounds such as Tellurium dioxide(TeO2)and Tellurite ion(TeO32-) in the mineral ore.(5,2)
Another application of the Erythrobacter Litoralis is that the its genome could provide informations about the LOV-histidine kinase system. LOV-histidine kinase system is used by the pathogen Brucella during its invasion of the host. light can increase the virulence of the Brucella who causes a "flu-like disorder Brucellosis" in cattles. Because Erythrobacter Litoralis is a aerobic phototrophic bacteria, it contains the sun-light sensors which have LOV domains. LOV is light, oxygen, and voltage.(6)
The Erythrobacter Litoralis can also be used for its ability of breaking down the organic matters, and therefore, the species helps recycling nutrients.(1)
Erythrobacter Litoralis is a newly discovered microbe, the bacteria is very important in many human's application. some of the current researches focus on the fact that the bacteria possess the LOV Histidine-kinase system. The group of Vladimir V. Yurkov is focusing on studying the LOV system using the Erythrobacter Litoralis. Another groups focus on the potential impact of the bacteria to the environment. The group of Briggs, Tseng, and SwartzMarcus is one of those pioneering in this field.(6,3,2)
2. Vladimir V. Yurkov* and J. Thomas Beatty. "AEROBIC ANOXYGENIC PHOTOTROPHIC BACTERIA," Journal List > Microbiol Mol Biol Rev > v.62(3); Sep 1998. PubMed articles by: Yurkov, V. Beatty, J. Microbiol Mol Biol Rev. 1998 September; 62(3): 695–724. Copyright © 1998, American Society for Microbiology <http://www.pubmedcentral.nih.gov/botrender.fcgi?blobtype=html&artid=98932>
3. Yurkov V , Stackebrandt E, Holmes A, Fuerst JA, Hugenholtz P, Golecki J, Gad'on N, Gorlenko VM, Kompantseva EI, Drews G. "Phylogenetic positions of novel aerobic, bacteriochlorophyll a-containing bacteria and description of Roseococcus thiosulfatophilus gen. nov., sp. nov., Erythromicrobium ramosum gen. nov., sp. nov., and Erythrobacter litoralis sp. nov," Int J Syst Bacteriol, 1994 Jul;44(3):427-34. <http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=7520734&ordinalpos=13&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum>.
4. Michal Koblížek · Oded Béjà · Robert R. Bidigare · Stephanie Christensen · Bryan Benitez-Nelson · Costantino Vetriani · Marcin K. Kolber · Paul G. Falkowski · Zbigniew S. Kolber. "Isolation and Characterization of Erythrobacter.strain from the upper ocean,"Arch Microbiol (2003) 180 : 327–338, DOI 10.1007/s00203-003-0596-6. Received: 14 March 2003 / Revised: 28 July 2003 / Accepted: 6 August 2003 / Published online: 23 September 2003. <http://marine.rutgers.edu/ebme/html_docs/reprints/Koblizek_ArchMicrobiol_180_327-338_2003.pdf>
5. Christopher Rathgeber, Natalia Yurkova, Erko Stackebrandt, J. Thomas Beatty, and Vladimir Yurkov1. " ISOLATION OF TELLURITE- and SELENITE-RESISTANT Bacteria from HYDROTHERMAL VENTS of THE JUAN de FUCA RIDGE in THE PACIFIC OCEAN," Applied and Environmental Microbiology, September 2002, p. 4613-4622, Vol. 68, No. 9. 0099-2240/02/$04.00+0. DOI: 10.1128/AEM.68.9.4613-4622.2002. Copyright ? 2002, American Society for Microbiology. All Rights Reserved. Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, R3T 2N2 Canada, Deutche Sammlung von Mikroorganismen und Zellkulturen Gmbh, D-38124 Braunschweig, Germany, Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, V6T 1Z3 Canada. Received 21 March 2002/ Accepted 21 June 2002.
6. Briggs, Tseng, and SwartzMarcus, A. Frederickson and Roberto A. Bogomolni, Gastón Paris and Fernando A. Goldbaum, Diego J. Comerci and Rodolfo A. Ugalde, Gireesh Rajashekara, Jung-Gun Kim and Mary Beth Mudgett. "NASTY BACTERIA NEED SUNLIGHT TO DO THEIR WORST," Public release date: 23-Aug-2007. <http://www.eurekalert.org/pub_releases/2007-08/ci-nbn082007.php>
Edited by Nhan Pham, student of Rachel Larsen.