Chromohalobacter Salexigens: Difference between revisions

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Bacteria; Proteobacteria; Gammaproteobacteria; Oceanospirillales; Halomonadaceae; Chromohalobacter;
Bacteria; Proteobacteria; Gammaproteobacteria; Oceanospirillales; Halomonadaceae; Chromohalobacter;
[[File:Sigs.2285059-f2.jpg‎‎|thumb|right|400px|"Chromohalobacter salexigens"[[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3368415/figure/f2/]]]]


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===Species===
===Species===


C. Salexigens
''C. salexigens''


==Description and significance==
==Description and significance==


[[Image: Chromohalobacter_Salexigens_BacMaps.png‎ |thumb|200px|right| Genome Sequence of C. Salexigens. Courtesy of[http://wishart.biology.ualberta.ca/BacMap/index.html BacMap Genome Atlas]]]


This bacterium is a moderate halophile(salt loving), yet does not require high concentrations of sodium chloride.  C. Salexigens is very flexible in that its salt requirements can be met by ions of other salts such as potassium, rubidium, ammonium, bromide, and others.
"C. salexigens" is a gram negative marine bacterium that lives in hypersaline environments. It was isolated from the island of Bonaire, Netherlands Antilles [6].This bacterium is a moderate halophile, with a broad salinity range''C. salexigens'' is very flexible in that its salt requirements can be met by ions of other salts such as potassium, rubidium, ammonium, bromide, and others [2]. It is an aerobic chemoorganotroph. It can live in a variety of saline conditions but their optimum concentration is between 2-2.5M [6].


==Genome structure==
==Genome structure==
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==Cell structure and metabolism==
==Cell structure and metabolism==


The growth rate of Chromohalobacter salexigens DSM 3043 can be stimulated in media containing 0.3 M NaCl by a 0.7 M concentration of other salts of Na+, K+, Rb+, or NH4+, Cl-, Br-, NO3-, or SO4(2-) ions.
The ability of ''C. salexigens'' to survive in a broad range of salinity, makes it a euryhaline bacterium [6]. "C. salexigens" can be considered extremophiles because they are able to survive in hypersaline conditions due to its osmoregulatory mechanisms, such as its production of ectoine. Its versatile metabolism allows for fast growth because of its ability to use a variety of simple carbon compounds as both its carbon and energy source. This bacterium compared, to other organisms that can live in high saline environments, has a more acidic amino acids that enable it to produce the organic solute, ectoine [7].  
 
==Ecology==


Edit: Placing Chromohalobacter salexigens in media containing a 0.3M concentration of NaCL and a 0.7M concentration of (Na+, K+, Rb+, etc...) will stimulate its growth positively.


==Ecology==
Interactions between ''C. salexigens'' and other bacterium such as various strands of Salmonella allow for salinity tolerance modulation.  In other words, this bacterium allows for other organisms to exist in environments they would otherwise not be able to cope with [4].
Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.
 
"C. salexigens" have the eight- gene cluster in order to from Isethionate from taurine, one of the simple compounds that this bacterium uses for its carbon and energy source. The formation of isethionate is used as nutrients for bacterium, "C. salexigens" create a reserve to use as nutrients for other bacterium [8].


==Pathology==
==Pathology==
Current research indicates that C. Salexigens is not known to be pathogenic.
Current research indicates that ''C. salexigens'' is not known to be pathogenic.


==Application to Biotechnology==
==Application to Biotechnology==


The halophilic bacterium Chromohalobacter salexigens synthesizes and accumulates compatible solutes in response to salt and temperature stress. The ectD gene, which is involved in the synthesis of the compatible solute hydroxyectoine, is essential for thermoprotection of the halophilic bacterium Chromohalobacter salexigens.
In response to salt and temperature stress ''C. salexigens'' produces and stores various solutes. Some solutes, namely hydroxyectoine, are used in thermoregulation processes that protect ''C. salexigens'' from extreme temperatures. [3]


==Current Research==
==Current Research==


N(gamma)-acetyl-2,4-diaminobutyrate (NADA), the precursor of the compatible solute ectoine, was shown to function as an osmoprotectant for the non-halophilic bacterium Salmonella enterica serovar Typhimurium. The addition of NADA-containing extracts of an ectoine synthase mutant of the broad salt-growing halophile Chromohalobacter salexigens DSM 3043(T) could alleviate the inhibitory effects of high salinity in S. enterica, which lacks the ectoine biosynthetic pathway. NADA, purified from extracts of the mutant, protected S. enterica against salinity stress.


In another study, the long-term response of the broad-salt growing halophile Chromohalobacter salexigens DSM 3043T to salt stress has been investigated with respect to adaptive changes in membrane lipid composition. This study included the wild-type and three salt-sensitive, ectoine-deficient strains: CHR62 (ectA::Tn1732, unable to grow above 0.75 M NaCl), CHR63 (ectC::Tn1732, unable to grow above 1.5 M NaCl), and CHR64, which was able to grow in minimal medium M63 up to 2.5 M NaCl, but its growth was slower than the wild-type strain at salinities above 1.5 M NaCl. This mutant accumulated ectoine and hydroxyectoine as major compatible solutes, but also the ectoine precursor, N-gamma-acetyldiaminobutyric acid, and was found to be affected in the ectoine synthase gene ectC. The main phospholipids of the wild-type strain were phosphatidylethanolamine, phosphatidylglycerol (PG), and cardiolipin (CL). Major fatty acids were detected as 16:0, 18:1, and 16:1, including significant amounts of cyc-19:0, and cyc-17:0. CL and cyclopropane fatty acids (CFA) levels were elevated when the wild-type strain was grown at high salinity (2.5 M NaCl). Membranes of the most salt-sensitive trains CHR62 and CHR63, but not of the less salt-sensitive strain CHR64, contained lower levels of CL. The proportion of cyc-19:0 in CHR64 was three-fold (at 2.0M NaCl) and 2.5-fold (at 2.5 M NaCl) lower than that of the wild type, suggesting that this mutant has a limited capacity to incorporate CFA into phospholipids at high salt. The addition of 1 mM ectoine to cultures of the wild-type strain increased the ratio PG/CL from 1.8 to 3.3 at 0.75 M NaCl, and from 1 to 6.5 at 2.5 M NaCl, and led to a slight decrease in CFA content. Addition of 1 mM ectoine to the mutants restored the steady-state levels of CL and CFA found in the wild-type strain supplemented with ectoine. These findings suggest that exogenous ectoine might attenuate the osmostress response involving changes in membrane lipids.
[[File:3034673_1752-0509-5-12-5.png ‎|thumb|right|400px|Ectoine biosynthesis pathways[[http://openi.nlm.nih.gov/detailedresult.php?img=3034673_1752-0509-5-12-5&query=the&fields=all&favor=none&it=none&sub=none&uniq=0&sp=none&req=4&simCollection=2795831_11999_2009_881_Fig5_HTML&npos=2&prt=3]]]]
 
"C. salexigens" are used as the model organism to test osmoadaptation, ectoine is a natural compound found in this bacterium and "C. salexigens" are osmoadaptive because of its' ability to biosynthesize ectoine [7].
 
Scientists are researching mutant ''C. salexigens'' bacterium that synthesize ectoine. ''C. Salexigens'' mutants can be used to produce N(gamma)-acetyl-2,4-diaminobutyrate (NADA). When mutants are placed in conjunction with the bacterium ''Salmonella Enterica Serovar Typhimurium'', salinity stress typically present in this form of Salmonella ceased to persist. [4]
 
In other research, ''C. Salexigens'' is being investigated to better understand its long-term response to salinity stress regarding membrane modulation. Ectoine-deficient strains of ''C. salexigens'' are unable to cope with salinity stress and undergo extensive membrane changes. The addition of ectoine to these deficient strains, however, allows these bacterium to maintain a salinity responsive membrane. [5]


==References==
==References==
[http://wishart.biology.ualberta.ca/BacMap/index.html Stothard P, Van Domselaar G, Shrivastava S, Guo A, O'Neill B, Cruz J, Ellison M, Wishart DS (2005) BacMap: an interactive picture atlas of annotated bacterial genomes. Nucleic Acids Res 33:D317-D320]
[1] [http://wishart.biology.ualberta.ca/BacMap/index.html Stothard P, Van Domselaar G, Shrivastava S, et. al. 2005. BacMap: an interactive picture atlas of annotated bacterial genomes. Nucleic Acids Res 33:D317-D320]
 
[2] [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=14532102&query_hl=2&itool=pubmed_docsum O'Connor K, Csonka LN. 2003. Salt Requirements of C. Salexigens. Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907-1392.]
 
[3] [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16707670&query_hl=2&itool=pubmed_docsum Garcia-Estepa R, Argandona M, Reina-Bueno M, et. al. 2006. Thermoprotection of C. Salexigens. Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Spain.]


[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=14532102&query_hl=2&itool=pubmed_docsum O'Connor K, Csonka LN. The high salt requirement of the moderate halophile Chromohalobacter salexigens DSM3043 can be met not only by NaCl but by other ions. Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907-1392.]
[4] [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16469465&query_hl=2&itool=pubmed_docsumGarcia-Estepa Garcia-Estepa R, Canovas D, Iglesias-Guerra F, et. al. 2006. Osmoprotection of Salmonella Enterica. Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Spain.]


[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16707670&query_hl=2&itool=pubmed_docsum Garcia-Estepa R, Argandona M, Reina-Bueno M, Capote N, Iglesias-Guerra F, Nieto JJ, Vargas C. The ectD gene, which is involved in the synthesis of the compatible solute hydroxyectoine, is essential for thermoprotection of the halophilic bacterium Chromohalobacter salexigens. Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, c/ Profesor Garcia Gonzalez 2, 41012 Seville, Spain.]
[5] [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16156114&query_hl=2&itool=pubmed_docsumGarcia-Estepa Vargas C, Kallimanis A, Koukkou AI, et. al. 2005. NADA, the Precursor to Ectoine. Department of Microbiology and Parasitology, University of Seville, Spain.]


[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16469465&query_hl=2&itool=pubmed_docsumGarcia-Estepa Garcia-Estepa R, Canovas D, Iglesias-Guerra F, Ventosa A, Csonka LN, Nieto JJ, Vargas C. Osmoprotection of Salmonella enterica serovar Typhimurium by Ngamma-acetyldiaminobutyrate, the precursor of the compatible solute ectoine. Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Seville, Spain.]
[6] [http://www.springerlink.com/content/v2tmu33122208324/ Oren, A, Larimer F, Richardson P, et al. 2005. How to be moderately halophilic with broad salt tolerance. Extremophiles. 9:275-279.]


[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16156114&query_hl=2&itool=pubmed_docsumGarcia-Estepa Vargas C, Kallimanis A, Koukkou AI, Calderon MI, Canovas D, Iglesias-Guerra F, Drainas C,Ventosa A, Nieto JJ. Osmoprotection of Salmonella enterica serovar Typhimurium by Ngamma-acetyldiaminobutyrate, the precursor of the compatible solute ectoine. Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain.]
[7] [http://www.biomedcentral.com/1752-0509/5/12 Ates O, Toksoy E, Arga K. 2011. Genome-scale reconstruction of metabolic network for a halophilic extremophile Chromohalobacter salexigens DSM 3043. BMC Systems Biology 5:12.]
 
[8] [http://mic.sgmjournals.org/content/156/5/1547.full Krejcik Z, Hollemeyer K, Smits T, Cook A. 2010. Isethionate formation from taurine in CHromohalobacter salexigens: purification of sulfoacetaldehyde reductase. Microbiology 156: 1547-1555.]






Edited by Chris Wittrock, a student of [mailto:ralarsen@ucsd.edu Rachel Larsen] and Kit Pogliano
Edited by Chris Wittrock, a student of [mailto:ralarsen@ucsd.edu Rachel Larsen] and Kit Pogliano
Revised by Sydney Rodman of Randolph-Macon College

Latest revision as of 00:17, 5 December 2012

This student page has not been curated.

A Microbial Biorealm page on the genus Chromohalobacter Salexigens

Classification

Higher order taxa

Bacteria; Proteobacteria; Gammaproteobacteria; Oceanospirillales; Halomonadaceae; Chromohalobacter;

"Chromohalobacter salexigens"[[1]]


NCBI: Taxonomy Genome

Species

C. salexigens

Description and significance

"C. salexigens" is a gram negative marine bacterium that lives in hypersaline environments. It was isolated from the island of Bonaire, Netherlands Antilles [6].This bacterium is a moderate halophile, with a broad salinity range. C. salexigens is very flexible in that its salt requirements can be met by ions of other salts such as potassium, rubidium, ammonium, bromide, and others [2]. It is an aerobic chemoorganotroph. It can live in a variety of saline conditions but their optimum concentration is between 2-2.5M [6].

Genome structure

DNA Bases: 3696649

Chromosome Type: Circular

Total Genes: 3403

Protein Coding Genes: 3319
RNA Genes:              84
Pseudo Genes:           21

Cell structure and metabolism

The ability of C. salexigens to survive in a broad range of salinity, makes it a euryhaline bacterium [6]. "C. salexigens" can be considered extremophiles because they are able to survive in hypersaline conditions due to its osmoregulatory mechanisms, such as its production of ectoine. Its versatile metabolism allows for fast growth because of its ability to use a variety of simple carbon compounds as both its carbon and energy source. This bacterium compared, to other organisms that can live in high saline environments, has a more acidic amino acids that enable it to produce the organic solute, ectoine [7].

Ecology

Interactions between C. salexigens and other bacterium such as various strands of Salmonella allow for salinity tolerance modulation. In other words, this bacterium allows for other organisms to exist in environments they would otherwise not be able to cope with [4].

"C. salexigens" have the eight- gene cluster in order to from Isethionate from taurine, one of the simple compounds that this bacterium uses for its carbon and energy source. The formation of isethionate is used as nutrients for bacterium, "C. salexigens" create a reserve to use as nutrients for other bacterium [8].

Pathology

Current research indicates that C. salexigens is not known to be pathogenic.

Application to Biotechnology

In response to salt and temperature stress C. salexigens produces and stores various solutes. Some solutes, namely hydroxyectoine, are used in thermoregulation processes that protect C. salexigens from extreme temperatures. [3]

Current Research

Ectoine biosynthesis pathways[[2]]

"C. salexigens" are used as the model organism to test osmoadaptation, ectoine is a natural compound found in this bacterium and "C. salexigens" are osmoadaptive because of its' ability to biosynthesize ectoine [7].

Scientists are researching mutant C. salexigens bacterium that synthesize ectoine. C. Salexigens mutants can be used to produce N(gamma)-acetyl-2,4-diaminobutyrate (NADA). When mutants are placed in conjunction with the bacterium Salmonella Enterica Serovar Typhimurium, salinity stress typically present in this form of Salmonella ceased to persist. [4]

In other research, C. Salexigens is being investigated to better understand its long-term response to salinity stress regarding membrane modulation. Ectoine-deficient strains of C. salexigens are unable to cope with salinity stress and undergo extensive membrane changes. The addition of ectoine to these deficient strains, however, allows these bacterium to maintain a salinity responsive membrane. [5]

References

[1] Stothard P, Van Domselaar G, Shrivastava S, et. al. 2005. BacMap: an interactive picture atlas of annotated bacterial genomes. Nucleic Acids Res 33:D317-D320

[2] O'Connor K, Csonka LN. 2003. Salt Requirements of C. Salexigens. Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907-1392.

[3] Garcia-Estepa R, Argandona M, Reina-Bueno M, et. al. 2006. Thermoprotection of C. Salexigens. Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Spain.

[4] Garcia-Estepa R, Canovas D, Iglesias-Guerra F, et. al. 2006. Osmoprotection of Salmonella Enterica. Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Spain.

[5] Vargas C, Kallimanis A, Koukkou AI, et. al. 2005. NADA, the Precursor to Ectoine. Department of Microbiology and Parasitology, University of Seville, Spain.

[6] Oren, A, Larimer F, Richardson P, et al. 2005. How to be moderately halophilic with broad salt tolerance. Extremophiles. 9:275-279.

[7] Ates O, Toksoy E, Arga K. 2011. Genome-scale reconstruction of metabolic network for a halophilic extremophile Chromohalobacter salexigens DSM 3043. BMC Systems Biology 5:12.

[8] Krejcik Z, Hollemeyer K, Smits T, Cook A. 2010. Isethionate formation from taurine in CHromohalobacter salexigens: purification of sulfoacetaldehyde reductase. Microbiology 156: 1547-1555.


Edited by Chris Wittrock, a student of Rachel Larsen and Kit Pogliano

Revised by Sydney Rodman of Randolph-Macon College