Congregibacter litoralis

{{Short description|Species of bacterium}} {{Taxobox | domain = Bacteria | phylum = Pseudomonadota | classis = Gammaproteobacteria | ordo = Cellvibrionales | familia = Halieaceae | genus = ''Congregibacter'' | species = '''''C. litoralis''''' | binomial = ''Congregibacter litoralis'' | binomial_authority = (Eliers 1999) | type_strain = KT71 }}

'''''Congregibacter litoralis''''' KT71 is a gram-negative ''Gammaproteobacteria'' part of the NOR5/OM60 Clade discovered in seawater from Heligoland, an island in the North Sea by H. Eilers from the Max Planck Institute for Microbiology.<ref name="D">{{cite journal | last1 = Eilers | first1 = H. | display-authors = etal | year = 2001 | title = Isolation of Novel Pelagic Bacteria from the German Bight and Their Seasonal Contributions to Surface Picoplankton | journal = Applied and Environmental Microbiology | volume = 67 | issue = 11 | pages = 5134–5142 | doi=10.1128/aem.67.11.5134-5142.2001 | pmid=11679337 | pmc=93282| bibcode = 2001ApEnM..67.5134E }}</ref><ref name="E">{{cite journal | last1 = Fuchs | first1 = B. | display-authors = etal | year = 2007 | title = Characterization of a marine ''Gammaproteobacterium'' capable of aerobic anoxygenic photosynthesis | journal = Proceedings of the National Academy of Sciences | volume = 104 | issue = 8 | pages = 2891–2896 | doi=10.1073/pnas.0608046104 | pmid=17299055 | pmc=1815277| doi-access = free }}</ref><ref name="C">{{cite journal | last1 = Yurkov | first1 = V. V. | last2 = Beatty | first2 = T. J. | year = 1998 | title = Aerobic anoxygenic phototrophic bacteria | pmc = 98932 | journal = Microbiology and Molecular Biology Reviews | volume = 62 | issue = 3 | pages = 695–724 | doi = 10.1128/MMBR.62.3.695-724.1998 | pmid=9729607}}</ref> ''C. litoralis'' KT71 is described as a pleomorphic bacterium and has a size of 2 x 0.5 μm.<ref name="E"/> When grown in culture, ''C. litoralis'' KT71 has a generation time of 4.5 hours and prefers to grow on complex substrates where the sole carbon source is undefined, though it can utilize some sole carbon sources because they are most likely used by the organism for its central metabolism.<ref name="D" /><ref name="E" /><ref name="G">{{cite journal | last1 = Schut | first1 = F | last2 = de Vries | first2 = EJ | last3 = Gottschal | first3 = JC | year = 1993 | title = Isolation of typical marine bacteria by dilution culture: growth, maintenance, and characteristics of isolates under laboratory conditions | journal = Appl. Environ. Microbiol. | volume = 59| issue = 7 | pages = 2150–2160| doi = 10.1128/AEM.59.7.2150-2160.1993 | pmid = 16348992 | pmc = 182250 | bibcode = 1993ApEnM..59.2150S }}</ref>

==Classification==

===Phylogeny=== ''Congregibacter litoralis'' KT71 was one of the first cultured members of OM60/NOR5 clade and is part of the aerobic anoxygenic phototrophs (AAnPs), a group of bacteria that include marine and freshwater ''Gamma''- and ''Alphaproteobacteria''.<ref name="D" /><ref name="E" /><ref name="C"/><ref name="G" /> Within the environment, members of the OM60/NOR5 clade are cosmopolitan in ocean environments, but seem to have a greater abundance in euphotic coastal marine areas.<ref name="A">{{cite journal | last1 = Yan | first1 = S. | display-authors = etal | year = 2009 | title = Biogeography and phylogeny of the NOR5/OM60 clade of Gammaproteobacteria | journal = Syst. Appl. Microbiol. | volume = 32 | issue = 2 | pages = 124–139 | doi=10.1016/j.syapm.2008.12.001| pmid = 19216045 }}</ref> In April 2015, ''C. litoralis'' KT71 was classified into the newly proposed Order of ''Cellvibrionales'' and Family ''Halieaceae''.<ref name="H">{{cite journal | pmc = 4391266 | pmid=25914684 | doi=10.3389/fmicb.2015.00281 | volume=6 | title=A taxonomic framework for emerging groups of ecologically important marine gammaproteobacteria based on the reconstruction of evolutionary relationships using genome-scale data | year=2015 | journal=Front Microbiol | page=281 | last1 = Spring | first1 = S | last2 = Scheuner | first2 = C | last3 = Göker | first3 = M | last4 = Klenk | first4 = HP| doi-access=free }}</ref> Within the OM60/NOR5 clade, ''Congregibacter litoralis'' KT71 clusters, based on the 16S rRNA gene with the genera ''Congregibacter'', ''Haliea'', ''Halioglobus'', ''Luminiphilus'', and ''Pseudohaliea''.<ref name="H" />

==Discovery and isolation== KT71 was first isolated from a surface water sample taken near Helgoland, an island in the North Sea by Eilers et al. in August 1999.<ref name="D" /> To isolate the organism, Eliers et al. used direct plating on complex low-nutrient media called MPM developed by Schut et al.<ref name="D" /><ref name="G" /> MPM was designed to mimic seawater. However, Eilers et al. modified this to adjust the pH to 7.5 and reduced NH4Cl and KH2PO4 to 50 and 1.5 μM, respectively.<ref name="D" /> Briefly, seawater was plated onto MPM and modified MPM and allowed to grow for 37 days. During the 37 days, colonies were picked and placed into liquid MPM culture.<ref name="D" />

==Basic genomic information== In 2004, ''C. litoralis'' KT71 was picked for whole genome sequencing.<ref name="E" /> To sequence the organism, plasmid and fosmid libraries were prepared with insert sizes of 4 and 40 kb. The clonal sequences were sequenced by an Applied Biosystems 3730XL DNA sequencer at the J. Craig Venter Science Foundation Joint Technology Center. From this, it was determined that ''C. litoralis'' KT71 had a genome size of 4.35Mbp with a GC content of 57.7%.<ref name="D" /> Moreover, the genome contains 3933 coding genes.<ref name="E" /> KT71's assembled genome was assessed for protein coding regions using the [https://www.ncbi.nlm.nih.gov/refseq/annotation_prok/ Prokaryotic Genomes Automatic Annotation Pipeline] (PGAAP) from the National Center for Biotechnology Information.<ref name="B" /> Once completed, genome annotation of the open reading frames was done with [https://sourceforge.net/p/gendb/news/ GenDB v2.2 annotation system].<ref name="B" />

==Metabolism== ''Congregibacter litoralis'' KT71 is an aerobic anoxygenic photoheterotroph (AAnPs).<ref name="E" /><ref name="F">{{cite journal | last1 = Spring | first1 = S. | last2 = Lünsdorf | first2 = H. | last3 = Fuchs | first3 = B. | last4 = Tindall | first4 = B. | year = 2009 | title = The Photosynthetic Apparatus and Its Regulation in the Aerobic Gammaproteobacterium Congregibacter litoralis gen. nov., sp. nov | journal = PLOS ONE | volume = 4| issue = 3 | article-number = e4866| doi = 10.1371/journal.pone.0004866 | pmid=19287491 | pmc=2654016| bibcode = 2009PLoSO...4.4866S | doi-access = free }}</ref> In general terms, this means that KT71 is a strict aerobic organism with preference for low-oxygen environments. To find these environments, KT71 uses a flagellum combined with chemotaxis to move towards low-oxygen areas.<ref name="E" /> Though it does contain a complete photosynthesis superoperon, KT71 cannot grow autotrophically.<ref name="E" /><ref name="F"/> Instead, KT71 uses light for light-dependent cyclic electron transport through its photosystem to generate a proton gradient.<ref name="E" /><ref name="F"/> To determine the metabolism of KT71, the organism was grown in mineral medium containing: 35.0 g of sea salts, 0.1 g of NH4Cl, 0.05 g of K2HPO4, and 10 ml of a vitamin solution.<ref name="B" /> The mineral medium was then supplemented with various carbon compounds to determine the ability for KT71 to use in its metabolism.<ref name="B" /><ref name="F" /> From this it was determined that KT71 can grow well with carbon sources such as glutamate, pyruvate, and fatty acids as well as more complex substrates like yeast extract and trypticase peptone.<ref name="B" /><ref name="F" /> Within its genome, genes, determined from genome annotation, involved in the pentose phosphate pathway, trichloroacetic acid cycle (TCA), citric acid cycle were found which correlated to the metabolism observed in culture.<ref name="E" /><ref name="F"/> Further, KT71 is unable to use glucose as a sole carbon source, which was supported by genome analysis that showed a lack of glucose metabolism genes.<ref name="E" /> Although the supplementation of inorganic sulfur to media did not promote growth, KT71 does contain sulfur-oxidizing (''sox'') genes that are uniquely arranged in its genome.<ref name="E" /> It is predicted that the potential use of the ''sox'' genes would be in the adenosine 5'-phosphosulfate (APS)/ 3'-Phosphoadenosine-5'-phosphosulfate (PAPS) pathway.<ref name="E" /><ref name="B">{{cite journal | last1 = Spring | first1 = S | year = 2014 | title = Function and Evolution of the Sox Multienzyme Complex in the Marine Gammaproteobacterium Congregibacter litoralis | doi = 10.1155/2014/597418 | journal = ISRN Microbiology | volume = 2014| pages = 1–11| pmid = 25006520 | pmc = 4003848 | doi-access = free }}</ref>

==Importance and role==

===Importance=== Though KT71 and other AAnPs can make up over 10% of the bacterioplanktonic community in oligotrophic oceans, more recent studies have shown them to be less important in open ocean and more important (over 15%) in eutrophic and mesotrophic coastal ocean regions.<ref name="E" /> Further, though AAnPs have been characterized previously in ''Alphaproteobacteria'', KT71 was the first ''Gammaproteobacteria'' AAnP to be isolated and suggest a potential for a second group of AAnPs.<ref name="E" /> KT71 will therefore serve as the model organism for this group to help shed light on the importance of ''Gammaproteobacteria'' AAnPs in the coastal environment.<ref name="E" />

===Role=== When grown in pure culture, it was observed under a microscope that KT71 formed aggregates.<ref name="E" /> These formations were supported by genome analysis in which genes coding for Type IV pili as well as extracellular polysaccharide production were found.<ref name="E" /> It was predicted by Fuchs et al. that KT71 uses the polysaccharide formation to help form marine snow.<ref name="E" /> KT71 uses these particles that are high in nutrients as a source of nutrients or live in a commensal relationship with other bacteria that provide the necessary compounds that KT71 uses for substrates.<ref name="E" />

==References== {{Reflist}}

==External links== *[http://bacdive.dsmz.de/index.php?search=17910&submit=Search Type strain of ''Congregibacter litoralis'' at Bac''Dive'' - the Bacterial Diversity Metadatabase]

Category:Gammaproteobacteria Category:Bacteria described in 1999