Photobacterium phosphoreum: Difference between revisions

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{{subpages}}
{{CZ:Biol_201:_General_Microbiology/EZnotice}}
{{Taxobox
| color = green
| name =  '''Photobacterium phosphoreum'''
| image = Photobacterium_phosphoreum.jpg
| regnum = [[Bacteria]]
| phylum = [[Proteobacteria]]
| classis = [[Gammaproteobacteria]]
| ordo = [[Vibrionales]] 
| familia = [[Vibrionaceae]]
| genus = ''[[Photobacterium]]''
| species = ''[[P. phosphoreum]]''
| binomial = ''[[Photobacterium phosphoreum]]''
| binomial_authority = 
}}
==Description and significance==
Photobacterium phosphoreum is a [[luminescent bacterium]]. They are gram-negative, straight rod, plump and large (0.8-1.3 um in diameter and 1.8-2.4 um in length). They can be motile or non-motile. Those that are motile have 1-3 unsheathed polar flagella. It can grow at low temperature, 4˚C, but no at 35˚C. They emit the brightest light from all bacteria [http://www.disknet.com/indiana_biolab/b203.htm]. Their [[optimum temperature]] is 18-25˚C [http://web.mst.edu/~microbio/BIO221_2005/P_phosphoreum.htm]. They emit a blue-green light due to the [[catalytic]] activity of [[luciferase]]. They are [[oxidase]] positive because they can use D-glucose as their principle carbon source (Prescott, Harley and Klein 557). They can be cultivated in Long and Hammer Agar (1% NaCl). It is known as a [[symbiotic]] bacterium that lives in the [[light organ]] of some marine fishes. It can also live freely in seawater, [[saprophytically]] and [[parasitically]] [http://aem.asm.org/cgi/content/full/69/11/6938].
Their major significance is their symbiotic relationship with some marine animals like fishes and squids. They have light organs that provide P. phosphoreum microorganisms with a safe place to inhabit and food; while these animals use the light that the bacteria provide for camouflage, communication and even for attracting mates or escape from predators [http://mrw.interscience.wiley.com/emrw/9780470015902/els/article/a0003064/current/html Only opens in QC]. Light emission can also aid to the propagation of the host. Another role that P. phosphoreum has is their ability of signaling the relative toxicity of a substance. This can happen due to the connection of the light producing process with the [[cellular metabolism]]. If the toxins disrupt the cellular metabolism, then the strength of the light produced decreases [http://web.mst.edu/~microbio/BIO221_2005/P_phosphoreum.htm].
==Genome structure==
==Genome structure==


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P. phosphoreum contains in its genome a lux gene that codes for the enzyme luciferase. It transforms chemical energy into light energy. Luciferase is a heterodimer with alpha and beta subunits. These two subunits are coded by luxA and luxB respectively.
P. phosphoreum contains in its genome a lux gene that codes for the enzyme luciferase. It transforms chemical energy into light energy. Luciferase is a heterodimer with alpha and beta subunits. These two subunits are coded by luxA and luxB respectively.
==Cell structure and metabolism==
P. phosphoreum belongs to the phylum [[Proteobacteria]]. All bacteria that belong to that phylum are known to be [[Gram-negative]]. As gram-negative P. phosphoreum contain an [[outer membrane]] made of [[lipopolysaccharide]] outside and inside [[phospholipids]], a [[periplasma space]], a thin [[peptidoglycan]] layer and finally the plasma membrane [http://mrw.interscience.wiley.com/emrw/9780470015902/els/article/a0000465/current/html?hd=All,Photobacterium&hd=All,phosphoreum?hd=All,Photobacterium&hd=All,phosphoreum Encyclopedia of Life Sciences].
P. phosphoreum is a [[chemoorganotroph]] which is capable of [[respiratory]] and [[fermentative]] metabolism [http://www.disknet.com/indiana_biolab/b203.htm]. It is a [[facultative anaerobe]] that can grow in the absence of oxygen when appropriate electron-acceptors are present. It doesn’t [[denitrify]]; in other word, it cannot use nitrogen molecules [http://www.disknet.com/indiana_biolab/b203.htm].
P. phosphoreum can produce blue-green light with the help of an enzyme called [[luciferase]]. “Luciferase catalyzes the reaction and uses reduced [[flavin]] [[mononucleotide]], molecular oxygen, and a long-chain aldehyde as substrate” (Prescott, Harley and Klein 559).
''Equation''
 
FMN''H''<sub>2</sub> + ''O''<sub>2</sub> + RCHO + luciferase &rarr; FMH + ''H''<sub>2</sub> + RCOOH + light
When the excited flavin intermediate (FMN) moves to [[ground state]], it emits the light which is one of the products of the reaction [http://www.microbelibrary.org/ASMOnly/Details.asp?ID=552]. "The [[bioluminescence]] [[quantum]] yield has been estimated to be 10–30%" [http://mrw.interscience.wiley.com/emrw/9780470015902/els/article/a0001412/current/html?hd=All,Photobacterium&hd=All,phosphoreum Encyclopedia of Life Sciences]. If you have observed in the photosynthetic equation reaction, oxygen is not produce therefore P. phosphoreum is known to have an [[anoxygenic photosynthesis]] [http://mrw.interscience.wiley.com/emrw/9780470015902/els/article/a0000465/current/html?hd=All,Photobacterium&hd=All,phosphoreum?hd=All,Photobacterium&hd=All,phosphoreum Encyclopedia of Life Sciences].
==Ecology==
P. phosphoreum is mostly considered a marine bacterium because sodium ions are required for its growth. It lives in the depth of the ocean, seawater, marine sediments, in the guts of marine animals, and on the surface of decomposing fish. When they are dispersed they produce a very weak light; however when they are very close to each other they produce light efficiently. P. phosphoreum acts as the light bulb in the in a dark environment like in the depth of the ocean [http://www.biology.pl/bakterie_sw/bac_mf_en.html Biology].
==Application to Biotechnology==
P. phosphoreum due to its bioluminescence ability is use in some biotechnology processes.
==Current Research==
==References==
{{reflist|11}}
http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=659
http://www.microbiologyatlas.kvl.dk/biologi/english/showmorf.asp?articleid=44
http://www.disknet.com/indiana_biolab/b203.htm
http://www.biology.pl/bakterie_sw/index_en.html
http://cibt.bio.cornell.edu/programs/archive/0608alum/lumos.pdf
http://web.mst.edu/~microbio/BIO221_2005/P_phosphoreum.htm
http://www.microbelibrary.org/ASMOnly/Details.asp?ID=552
Willey, Joanne, Linda Sherwood and Christopher Woolverton. ''Prescott, Harley, and Klein's Microbiology''. 7th ed. New York: New York, 2008.
http://mrw.interscience.wiley.com/emrw/9780470015902/els/article/a0003064/current/html
http://mrw.interscience.wiley.com/emrw/9780470015902/els/article/a0000465/current/html?hd=All,Photobacterium&hd=All,phosphoreum?hd=All,Photobacterium&hd=All,phosphoreum
http://www.moore.org/microgenome/detail.aspx?id=36

Revision as of 19:51, 20 April 2009

Genome structure

Photobacterium phosphoreum major lineage is Gammaproteobacteria. It contains a single circular chromosome. The genome size is about 4.0 Mb. It has a G+C content of genomic DNA of 41%. The number of genes are 4576. The coding percent is 84.0%. It can be isolated by using plating methods Microbial Genome Sequencing Project.

The 16S rRNA gene sequence (By Åke Hagström):

GAGTTTGATCCTGGCTCAGATTGAACGCTGGCGGCAGGCCTAACACATGCAAGTCGAGCGGTAACAGATTGATAGCTTGCTATCAATGCTGACGAGCGGCGGACGGGTGAGTAATGCCTGGGAAT ATGCCCTGATGTGGGGGATAACTATTGGAAACGATAGCTAATACCGCATAATCTCTTCGGAGCAAAGAGGGGGACCTTCGGGCCTCTCGCGTCAGGATTAGCCCAGGTGGGATTAGCTTGTTGGT GGGGTAATGGCTCACCAAGGCGACGATCCCTAGCTGGTCTGAGAGGATGATCAGCCACACTGGAACTGAGACACGGTCCAGACTCCTACGGGAGGCAGCAGTGGGGAATATTGCACAATGGGGGA AACCCTGATGCAGCCATGCCGCGTGTATGAAGAAGGCCTTCGGGTTGTAAAGTACTTTCAGTTGTGAGGAAGGCAGTAAAGTTAATAGCTTTATTGTTTGACGTTAGCAACAGAAGAAGCACCGG CTAACTCCGTGCCAGCAGCCGCGGTAATACGGAGGGTGCGAGCGTTAATCGGAATTACTGGGCGTAAAGCGCATGCAGGTGGTCTGTTAAGCAAGATGTGAAAGCCCGGGGCTCAACCTCGGAAC AGCATTTTGAACTGGCAGACTAGAGTACTGTAGAGGGGGGTAGAATTTCAGGTGTAGCGGTGAAATGCGTAGAGATCTGAAGGAATACCGGTGGCGAAGGCGGCCCCCTGGACAGATACTGACAC TCAGATGCGAAAGCGTGGGGAGCAAACAGGATTAGATACCCTGGTAGTCCACGCCGTAAACGATGTCTACTTGGAGGTTGTGGCCTTGAGCCGTGGCTTTCGGAGCTAACGCGTTAAGTAGACCG CCTGGGGAGTACGGTCGCAAGATTAAAACTCAAATGAATTGACGGGGGCCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGATGCAACGCGAAGAACCTTACCTACTCTTGACATCCAGAGAAC TTTCCAGAGATGGATTGGTGCCTTCGGGAACTCTGAGACAGGTGCTGCATGGCTGTCGTCAGCTCGTGTTGTGAAATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCTTATCCTTGTTTGCCAG CACATAATGGTGGGAACTCCAGGGAGACTGCCGGTGATAAACCGGAGGAAGGTGGGGACGACGTCAAGTCATCATGGCCCTTACGAGTAGGGCTACACACGTGCTACAATGGCGTATACAGAGGG CTGCCAACTAGCGATAGTGAGCGAATCCCAGAAAGTACGTCGTAGTCCGGATTGGAGTCTGCAACTCGACTCCATGAAGTCGGAATCGCTAGTAATCGTGAATCAGAATGTCACGGTGAATACGT TCCCGGGCCTTGTACACACCGCCCGTCACACCATGGGAGTGGGCTGCACCAGAAGTAGATAGCTTAACCTTCGGGAGGGCGTTTACCACGGTGTGGTTCATGACTGGGGTGAAGTCGTAACAAGG TAACC

P. phosphoreum contains in its genome a lux gene that codes for the enzyme luciferase. It transforms chemical energy into light energy. Luciferase is a heterodimer with alpha and beta subunits. These two subunits are coded by luxA and luxB respectively.

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