Editing Prochlorococcus (section)

==Morphology==
Marine cyanobacteria are to date the smallest known [[Photosynthesis|photosynthetic]] organisms; ''Prochlorococcus'' is the smallest at just 0.5 to 0.7 micrometres in diameter.<ref name="Biller-2014">{{cite journal|last1=Biller|first1=Steven J.|last2=Berube|first2=Paul M.|last3=Lindell|first3=Debbie|author-link3=Debbie Lindell|last4=Chisholm|first4=Sallie W.|title=Prochlorococcus: the structure and function of collective diversity|journal=Nature Reviews Microbiology|date=1 December 2014|volume=13|issue=1|pages=13–27|doi=10.1038/nrmicro3378|pmid=25435307|url=https://dspace.mit.edu/bitstream/1721.1/97151/2/NRM_final_wfigs%20for%20Dspace.pdf|hdl=1721.1/97151|s2cid=18963108|hdl-access=free}}</ref><ref name="www.hup.harvard.edu" /> The coccoid shaped cells are non-motile and free-living. Their small size and large [[surface-area-to-volume ratio]], gives them an advantage in nutrient-poor water. Still, it is assumed that ''Prochlorococcus'' have a very small nutrient requirement.<ref name="Partensky">{{cite journal | url= | volume=63 | issue=1 | title=''Prochlorococcus'', a marine photosynthetic prokaryote of global significance | year=1999 | pages=106–127 |vauthors=Partensky F, Hess WR, Vaulot D | journal=Microbiology and Molecular Biology Reviews | pmid = 10066832 | pmc=98958| doi=10.1128/MMBR.63.1.106-127.1999 }}</ref> Moreover, ''Prochlorococcus'' have adapted to use [[sulfolipids]] instead of phospholipids in their membranes to survive in phosphate deprived environments.<ref name="Sulfolipid">{{cite journal|last1=Van Mooy|first1=B. A. S.|last2=Rocap|first2=G.|last3=Fredricks|first3=H. F.|last4=Evans|first4=C. T.|last5=Devol|first5=A. H.|title=Sulfolipids dramatically decrease phosphorus demand by picocyanobacteria in oligotrophic marine environments|journal=Proceedings of the National Academy of Sciences|date=26 May 2006|volume=103|issue=23|pages=8607–12|doi=10.1073/pnas.0600540103|pmid=16731626|pmc=1482627|bibcode=2006PNAS..103.8607V|doi-access=free}}</ref> This adaptation allows them to avoid competition with heterotrophs that are dependent on phosphate for survival.<ref name="Sulfolipid" /> Typically, ''Prochlorococcus'' divide once a day in the subsurface layer or oligotrophic waters.<ref name="Partensky"/>