Microorganism: Difference between revisions

Turkish scientist [[Akshamsaddin]] (Turkish scientist) mentioned the microbe in his work ''Maddat ul-Hayat'' (The Material of Life) about two centuries prior to [[Antonie van Leeuwenhoek]]'s discovery through experimentation:

Microorganisms can be found almost anywhere on [[Earth]]. [[Bacteria]] and [[archaea]] are almost always microscopic, while a number of [[eukaryote]]s are also microscopic, including most [[Protista|protists]], some [[fungus|fungi]], as well as some [[micro-animal]]s and plants. [[Virus]]es are generally regarded as [[Non-cellular life|not living]] and therefore not considered to be microorganisms, although a subfield of [[microbiology]] is [[virology]], the study of viruses.<ref>{{Cite book |title=eLS|last=Lim|first=Daniel V. |date=2001 |publisher=John Wiley |isbn=978-0-470-01590-2 |doi=10.1038/npg.els.0000459|chapter = Microbiology}}</ref><ref>{{Cite web|url=http://www.highveld.com/microbiology/what-is-microbiology.html|title=What is Microbiology? |website=highveld.com |access-date=2017-06-02|archive-url=https://web.archive.org/web/20150215180557/http://www.highveld.com/microbiology/what-is-microbiology.html |archive-date=2015-02-15}}</ref><ref>{{cite book |last=Cann |first=Alan |title=Principles of Molecular Virology |year=2011 |publisher=Academic Press |isbn=978-0-12-384939-7 |edition=5}}</ref>

{{further|Timeline of evolutionthe evolutionary history of life|Earliest known life forms}}

Single-celled microorganisms were the [[Origin of life|first forms of life]] to develop on Earth, approximately 3.5 [[gigaannum|billion years]] ago.<ref>{{Cite journal |author=Schopf, J. |title=Fossil evidence of Archaean life |journal=Philos Trans R Soc Lond B Biol Sci |volume=361 |issue=1470 |pages=869–885 |year=2006 |pmid=16754604 |doi=10.1098/rstb.2006.1834 |pmc=1578735}}</ref><ref>{{Cite journal |author=Altermann, W. |author2=Kazmierczak, J. |title=Archean microfossils: a reappraisal of early life on Earth |journal=Res Microbiol |volume=154 |issue=9 |pages=611–7 |year=2003 |pmid=14596897 | doi=10.1016/j.resmic.2003.08.006|doi-access=free }}</ref><ref>{{Cite journal|author=Cavalier-Smith, T. |author-link=Thomas Cavalier-Smith |title=Cell evolution and Earth history: stasis and revolution |journal=Philos Trans R Soc Lond B Biol Sci |volume=361 |issue=1470 |pages=969–1006 |year=2006 |pmid=16754610 |doi=10.1098/rstb.2006.1842 |pmc=1578732}}</ref> Further evolution was slow,<ref>{{Cite journal| author=Schopf, J. | title=Disparate rates, differing fates: tempo and mode of evolution changed from the Precambrian to the Phanerozoic | pmc=44277| journal=PNAS | volume=91 | issue=15 | pages=6735–6742 | year=1994 | pmid=8041691 | doi=10.1073/pnas.91.15.6735 | bibcode=1994PNAS...91.6735S| doi-access=free }}</ref> and for about 3&nbsp;billion years in the [[Precambrian]] [[Eon (geology)|eon]], (much of the history of [[life|life on Earth]]), all [[organism]]s were microorganisms.<ref>{{Cite journal|author=Stanley, S. |title=An Ecological Theory for the Sudden Origin of Multicellular Life in the Late Precambrian |journal=PNAS |volume=70 |issue=5 |pages=1486–1489 |date=May 1973 |pmid=16592084 |pmc=433525 | doi=10.1073/pnas.70.5.1486 |bibcode=1973PNAS...70.1486S |doi-access=free }}</ref><ref>{{Cite journal |author1=DeLong, E. |author2=Pace, N. | title=Environmental diversity of bacteria and archaea | journal=Syst Biol | volume=50 | issue=4 | pages=470–8 | year=2001 |pmid=12116647 | doi=10.1080/106351501750435040|citeseerx=10.1.1.321.8828 }}</ref> Bacteria, algae and fungi have been identified in [[amber]] that is 220&nbsp;million years old, which shows that the [[Morphology (biology)|morphology]] of microorganisms has changed little since at least the [[Triassic]] period.<ref>{{Cite journal |author=Schmidt, A. |author2=Ragazzi, E. |author3=Coppellotti, O. |author4=Roghi, G. | title=A microworld in Triassic amber | journal=Nature | volume=444 | issue=7121 | page=835 | year=2006 | pmid=17167469 | doi=10.1038/444835a |bibcode=2006Natur.444..835S |s2cid=4401723 | doi-access=free }}</ref> The newly discovered [[Nickel#Biological role|biological role played by nickel]], however – especially that brought about by [[Types of volcanic eruption|volcanic eruptions]] from the [[Siberian Traps]] – may have accelerated the evolution of [[methanogen]]s towards the end of the [[Permian–Triassic extinction event]].<ref>{{cite web |url= http://www.space.com/26654-microbe-innovation-started-largest-earth-extinction.html |title= Microbe's Innovation May Have Started Largest Extinction Event on Earth |last= Schirber |first=Michael |date= 27 July 2014 |publisher=Astrobiology Magazine |website= Space.com |quote=That spike in nickel allowed methanogens to take off.}}</ref>

Archaea differ from bacteria in both their genetics and biochemistry. For example, while bacterial [[cell membrane]]s are made from [[phospholipid|phosphoglycerides]] with [[ester]] bonds, archaean membranes are made of [[ether lipid]]s.<ref>{{Cite journal |author1=De Rosa, M. |author2=Gambacorta, A. | author3=Gliozzi, A. |title=Structure, biosynthesis, and physicochemical properties of archaebacterial lipids |journal=Microbiol. Rev. |volume=50 |issue=1 |pages=70–80 |date=1 March 1986|pmid=3083222 |pmc=373054 |doi=10.1128/mmbr.50.1.70-80.1986}}</ref> Archaea were originally described as [[extremophile]]s living in [[extreme environment]]s, such as [[hot spring]]s, but have since been found in all types of [[habitat]]s.<ref>{{Cite journal |author1=Robertson, C. |author2=Harris, J. |author3=Spear, J. |author4=Pace, N. | title=Phylogenetic diversity and ecology of environmental Archaea | journal=Curr Opin Microbiol | volume=8 | issue=6 | pages=638–42 | year=2005 | pmid=16236543 | doi=10.1016/j.mib.2005.10.003}}</ref> Only now are scientists beginning to realize how common archaea are in the environment, with [[Thermoproteota]] (formerly Crenarchaeota) being the most common form of life in the ocean, dominating ecosystems below {{convert|150 |m}} in depth.<ref>{{Cite journal |author=Karner, M.B. |author2=DeLong, E.F. |author3=Karl, D.M. |title=Archaeal dominance in the mesopelagic zone of the Pacific Ocean |journal=Nature |volume=409 |issue=6819 |pages=507–10 |year=2001 |pmid=11206545 | doi=10.1038/35054051|bibcode=2001Natur.409..507K |s2cid=6789859 }}</ref><ref>{{Cite journal |author=Sinninghe Damsté, J.S. |author2=Rijpstra, W.I. |author3=Hopmans, E.C. |author4=Prahl, F.G. |author5=Wakeham, S.G. |author6=Schouten, S. |title=Distribution of Membrane Lipids of Planktonic Crenarchaeota in the Arabian Sea |journal=Appl. Environ. Microbiol. |volume=68 |issue=6 |pages=2997–3002 |date=June 2002 |pmid=12039760 |pmc=123986 | doi=10.1128/AEM.68.6.2997-3002.2002|bibcode=2002ApEnM..68.2997S }}</ref> These organisms are also common in soil and play a vital role in [[ammonia]] oxidation.<ref name=LeiningerUrich2006>{{cite journal |last1=Leininger |first1=S. |last2=Urich |first2=T. |last3=Schloter |first3=M. |last4=Schwark |first4=L.|last5=Qi|first5=J. |last6=Nicol |first6=G. W. |last7=Prosser |first7=J. I. |author-link7=James I. Prosser |last8=Schuster |first8=S. C. |last9=Schleper |first9=C.|title=Archaea predominate among ammonia-oxidizing prokaryotes in soils |journal=[[Nature (journal)|Nature]] |volume=442 |issue=7104 |year=2006|pages=806–809|pmid= 16915287 |doi=10.1038/nature04983|bibcode=2006Natur.442..806L|s2cid=4380804 }}</ref>

The combined domains of archaea and bacteria make up the most diverse and abundant group of [[organism]]s on Earth and inhabit practically all environments where the temperature is below +{{convert|140&nbsp;|°C}}. They are found in [[water]], [[soil]], [[Earth's atmosphere|air]], as the [[microbiome]] of an organism, [[hot spring]]s and even deep beneath the Earth's crust in [[Rock (geology)|rocks]].<ref name=Gold>{{Cite journal|author=Gold, T. |title=The deep, hot biosphere |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=89 |issue=13 |pages=6045–9 |year=1992 |pmid=1631089 |doi= 10.1073/pnas.89.13.6045 |pmc=49434 |bibcode=1992PNAS...89.6045G|doi-access=free }}</ref> The number of prokaryotes is estimated to be around five nonillion, or 5 × 10³⁰, accounting for at least half the [[Biomass (ecology)|biomass]] on Earth.<ref>{{Cite journal|author=Whitman, W. |author2=Coleman, D. |author3=Wiebe, W. | title=Prokaryotes: The unseen majority | doi= 10.1073/pnas.95.12.6578 | journal=PNAS | volume=95 | issue=12 | pages=6578–83 | year=1998 | pmid=9618454 | pmc=33863|bibcode=1998PNAS...95.6578W |doi-access=free }}</ref>

The biodiversity of the prokaryotes is unknown, but may be very large. A May 2016 estimate, based on laws of scaling from known numbers of species against the size of organism, gives an estimate of perhaps 1&nbsp;trillion species on the planet, of which most would be microorganisms. Currently, only one-thousandth of one percent of that total have been described.<ref name="NSF-2016002">{{cite news |author=Staff |title=Researchers find that Earth may be home to 1 trillion species |url=https://www.nsf.gov/news/news_summ.jsp?cntn_id=138446 |date=2 May 2016 |work=[[National Science Foundation]] |access-date=6 May 2016 }}</ref> [[Archaea|Archael cells]] of some species aggregate and transfer [[DNA]] from one cell to another through direct contact, particularly under stressful environmental conditions that cause [[DNA damage (naturally occurring)|DNA damage]].<ref>{{cite journal |last1=van Wolferen |first1=M|last2=Wagner |first2=A|last3=van der Does |first3=C|last4=Albers |first4=SV | year = 2016 | title = The archaeal Ced system imports DNA | journal = Proc Natl Acad Sci U S A | volume = 113 | issue = 9| pages = 2496–501 | doi = 10.1073/pnas.1513740113 | pmid = 26884154 | pmc = 4780597 | bibcode = 2016PNAS..113.2496V | doi-access = free }}</ref><ref>Bernstein H, Bernstein C. Sexual communication in archaea, the precursor to meiosis. pp. 103-117 in Biocommunication of Archaea (Guenther Witzany, ed.) 2017. Springer International Publishing {{ISBN|978-3-319-65535-2}} DOI 10.1007/978-3-319-65536-9</ref>

Bacteria likeLike archaea, bacteria are prokaryotic – unicellular, and having no cell nucleus or other membrane-bound organelle. Bacteria are microscopic, with a few extremely rare exceptions, such as ''[[Thiomargarita namibiensis]]''.<ref>{{Cite journal |author=Schulz, H. |author2=Jorgensen, B. | title=Big bacteria | journal=Annu Rev Microbiol | volume=55 | pages=105–37 | year =2001 |pmid=11544351 | doi=10.1146/annurev.micro.55.1.105}}</ref> Bacteria function and reproduce as individual cells, but they can often aggregate in multicellular [[Colony (biology)#Microbial colony|colonies]].<ref>{{Cite journal |author-link=James A. Shapiro |author=Shapiro, J.A. |title=Thinking about bacterial populations as multicellular organisms |journal=Annu. Rev. Microbiol. |volume=52 |pages=81–104 |year=1998 |pmid=9891794 |doi=10.1146/annurev.micro.52.1.81 |url=http://www.sci.uidaho.edu/newton/math501/Sp05/Shapiro.pdf |url-status=dead |archive-url=https://web.archive.org/web/20110717183759/http://www.sci.uidaho.edu/newton/math501/Sp05/Shapiro.pdf |archive-date=17 July 2011 }}</ref> Some species such as [[myxobacteria]] can aggregate into complex [[swarm]]ing structures, operating as multicellular groups as part of their [[Biological life cycle|life cycle]],<ref>{{cite journal | title=Myxobacteria: Moving, Killing, Feeding, and Surviving Together | journal=Frontiers in Microbiology| volume=7| pages=781| pmid=27303375| pmc=4880591| year=2016| last1=Muñoz-Dorado| first1=J. | last2=Marcos-Torres| first2=F. J. | last3=García-Bravo | first3=E. | last4=Moraleda-Muñoz| first4=A. | last5=Pérez| first5=J. | doi=10.3389/fmicb.2016.00781| doi-access=free}}</ref> or form clusters in [[colony (biology)|bacterial colonies]] such as ''[[E.coli]]''.

Their [[genome]] is usually a [[circular bacterial chromosome]] – a single loop of [[DNA]], although they can also harbor small pieces of DNA called [[plasmid]]s. These plasmids can be transferred between cells through [[bacterial conjugation]]. Bacteria have an enclosing [[Bacterial cell structure#Cell wall|cell wall]], which provides strength and rigidity to their cells. They reproduce by [[binary fission]] or sometimes by [[budding]], but do not undergo [[Meiosis|meiotic]] [[sexual reproduction]]. However, many bacterial species can transfer DNA between individual cells by a [[horizontal gene transfer]] process referred to as natural [[Transformation (genetics)|transformation]].<ref>{{cite journal |author=Johnsbor, O. |author2=Eldholm, V. |author3=Håvarstein, L.S. |title=Natural genetic transformation: prevalence, mechanisms and function |journal=Res. Microbiol. |volume=158 |issue=10 |pages=767–78 |date=December 2007 |pmid=17997281 |doi=10.1016/j.resmic.2007.09.004 |doi-access=free }}</ref> Some species form extraordinarily resilient [[endospore|spores]], but for bacteria this is a mechanism for survival, not reproduction. Under optimal conditions bacteria can grow extremely rapidly and their numbers can double as quickly as every 20 minutes.<ref>{{Cite journal| author=Eagon, R. | title=Pseudomonas Natriegens, a Marine Bacterium With a Generation Time of Less Than 10 Minutes | journal=J Bacteriol | volume=83 | issue=4| pages=736–7 | year =1962 | pmid=13888946 | pmc=279347| doi=10.1128/JB.83.4.736-737.1962 }}</ref>

Of [[Eukaryote|eukaryotic]] groups, the [[protists]] are most commonly [[unicellular]] and microscopic. This is a highly diverse group of organisms that are not easy to classify.<ref>{{Cite journal|author=Cavalier-Smith T |author-link=Thomas Cavalier-Smith |title=Kingdom protozoa and its 18 phyla |journal=Microbiol. Rev. |volume=57 |issue=4 |pages=953–994 |date=1 December 1993|pmid=8302218 |pmc=372943 |doi=10.1128/mmbr.57.4.953-994.1993 |doi-access=free }}</ref><ref>{{Cite journal|author=Corliss JO |title=Should there be a separate code of nomenclature for the protists? |journal=BioSystems |volume=28 |issue=1–3 |pages=1–14 |year=1992 |pmid=1292654 | doi=10.1016/0303-2647(92)90003-H|bibcode=1992BiSys..28....1C }}</ref> Several [[algae]] [[species]] are [[multicellular]] protists, and [[slime mold]]s have unique life cycles that involve switching between unicellular, colonial, and multicellular forms.<ref>{{Cite journal|author=Devreotes P |title=Dictyostelium discoideum: a model system for cell-cell interactions in development |journal=Science |volume=245 |issue=4922 |pages=1054–8 |year=1989 |pmid=2672337 | doi=10.1126/science.2672337|bibcode=1989Sci...245.1054D }}</ref> The number of species of protists is unknown since only a small proportion has been identified. Protist diversity is high in oceans, deep sea-vents, river sediment and an acidic river, suggesting that many eukaryotic microbial communities may yet be discovered.<ref>{{Cite journal|author=Slapeta, J |author2=Moreira, D |author3=López-García, P. |title=The extent of protist diversity: insights from molecular ecology of freshwater eukaryotes |journal=Proc. Biol. Sci. |volume=272 |issue=1576 |pages=2073–2081 |year=2005 |pmid=16191619 |doi=10.1098/rspb.2005.3195 |pmc=1559898}}</ref><ref>{{Cite journal |author=Moreira, D. |author2=López-García, P. |title=The molecular ecology of microbial eukaryotes unveils a hidden world |journal=Trends Microbiol. |volume=10 |issue=1 |pages=31–8 |year=2002 |pmid=11755083 | url=http://download.bioon.com.cn/view/upload/month_0803/20080326_daa08a6fdb5d38e3a0d8VBrocN3WtOdR.attach.pdf | doi=10.1016/S0966-842X(01)02257-0}}</ref>

[[Extremophiles]] are microorganisms that have adapted so that they can survive and even thrive in [[extreme environment]]s that are normally fatal to most life-forms. [[Thermophile]]s and [[hyperthermophiles]] thrive in high [[temperature]]s. [[Psychrophile]]s thrive in extremely low temperatures. – Temperatures as high as {{convert|130|°C|°F}},<ref>[[Strain 121]], a [[Hyperthermophile|hyperthermophilic]] [[archaea]], has been shown to reproduce at {{convert|121|°C|°F}}, and survive at {{convert|130|°C|°F}}.[https://www.nsf.gov/od/lpa/news/03/pr0384.htm]</ref> as low as {{convert|-17|°C|°F}}<ref>Some [[Psychrophiles|Psychrophilic]] bacteria can grow at {{convert|-17|°C|°F}}),[http://news.bbc.co.uk/1/hi/sci/tech/827063.stm] and can survive near [[absolute zero]]).{{cite web |title=Earth microbes on the Moon |url=https://science.nasa.gov/newhome/headlines/ast01sep98_1.htm |url-status=dead |archive-url=https://web.archive.org/web/20100323224432/http://science.nasa.gov/newhome/headlines/ast01sep98_1.htm |archive-date=23 March 2010 |access-date=2009-07-20}}</ref> [[Halophile]]s such as ''[[Halobacterium salinarum]]'' (an archaean) thrive in high [[Salinity|salt conditions]], up to saturation.<ref>Dyall-Smith, Mike, [http://www.microbiol.unimelb.edu.au/people/dyallsmith/ ''HALOARCHAEA''], University of Melbourne. See also [[Haloarchaea]].</ref> [[Alkaliphile]]s thrive in an [[alkaline]] [[pH]] of about 8.5–11.<ref>{{Cite journal|url=http://jb.asm.org/cgi/reprint/185/2/461.pdf|title=''Bacillus alcalophilus'' can grow at up to pH 11.5|journal=Journal of Bacteriology|date=15 January 2003|volume=185|issue=2|pages=461–465|doi=10.1128/JB.185.2.461-465.2003|last1=Olsson|first1=Karen|last2=Keis|first2=Stefanie|last3=Morgan|first3=Hugh W.|last4=Dimroth|first4=Peter|last5=Cook|first5=Gregory M.|pmid=12511491|pmc=145327}}</ref> [[Acidophile]]s can thrive in a pH of 2.0 or less.<ref>[[Picrophilus]] can grow at pH −0.06.[http://www.rcn.montana.edu/resources/organisms/organisminfo.aspx?nav=11&tid=1298&did=1&nid=82076&lid=9] {{Webarchive|url=https://web.archive.org/web/20100622184325/http://www.rcn.montana.edu/resources/organisms/organisminfo.aspx?nav=11&tid=1298&did=1&nid=82076&lid=9 |date=22 June 2010 }}</ref> [[Piezophile]]s thrive at very [[high pressure]]s: up to 1,000–2,000 [[Atmosphere (unit)|atm]], down to 0 atm as in a [[vacuum]] of [[Outer space|space]].<ref>{{efn|The [[Piezophile|piezophilic]] bacteria [[Halomonas salaria]] requires a pressure of 1,000 atm; [[nanobes]], a speculative organism, have been reportedly found in the earth's crust at 2,000 atm.[<ref>{{cite web | url=http://www.microscopy-uk.org.uk/index.html?http://www.microscopy-uk.org.uk/nanobes/nanopaper.html] | title=Microscopy-UK Home (Resources for the microscopy enthusiast and amateur, including free monthly e-zine, Micscape.) }}</ref>}} A few extremophiles such as ''[[Deinococcus radiodurans]]'' are [[radioresistance|radioresistant]],<ref>{{cite journal | volume=10 | issue=1 | pages=575–577 | last=Anderson | first=A. W. |author2=Nordan, H. C. |author3=Cain, R. F. |author4=Parrish, G. |author5=Duggan, D. | title=Studies on a radio-resistant micrococcus. I. Isolation, morphology, cultural characteristics, and resistance to gamma radiation | journal=Food Technol. | year=1956}}</ref> resisting [[Ionizing radiation|radiation]] exposure of up to 5k [[Gray (unit)|Gy]]. Extremophiles are significant in different ways. They extend terrestrial life into much of the Earth's [[hydrosphere]], [[Crust (geology)|crust]] and [[atmosphere]], their specific evolutionary adaptation mechanisms to their extreme environment can be exploited in [[biotechnology]], and their very existence under such extreme conditions increases the potential for [[extraterrestrial life]].<ref>{{cite journal |author=Cavicchioli, R. |title=Extremophiles and the search for extraterrestrial life |journal=Astrobiology |volume=2 |issue=3 |pages=281–292 |year=2002 |pmid=12530238 |doi=10.1089/153110702762027862 |bibcode=2002AsBio...2..281C |url=http://somosbacteriasyvirus.com/extremophiles.pdf |citeseerx=10.1.1.472.3179 |access-date=26 October 2017 |archive-date=26 April 2022 |archive-url=https://web.archive.org/web/20220426071811/https://somosbacteriasyvirus.com/extremophiles.pdf |url-status=dead }}</ref>

===Plants and Soilsoil===

Some|+Example industrial uses of Microorganisms: microorganisms

!scope="row"|Cheese

!scope="row"|Alcoholic beverages

|yeast is used to convert sugar, grape juice, or malt-treated grain into alcohol. other microorganisms may also be used; a mold converts starch into sugar to make the Japanese rice wine, sake. ''[[Acetobacter aceti|Acetobacter Aceti]]'' a kind of bacterium is used in production of Alcoholic beverages

!scope="row"|Vinegar

!scope="row"|Citric acid

!scope="row"|Vitamins

!scope="row"|Antibiotics

Microorganisms are the causative agents ([[pathogen]]s) in many [[Infection|infectious diseases]]. The organisms involved include [[pathogenic bacteria]], causing diseases such as [[bubonic plague|plague]], [[tuberculosis]] and [[anthrax]]; [[protozoa]]n [[parasite]]s, causing diseases such as [[malaria]], [[African trypanosomiasis|sleeping sickness]], [[dysentery]] and [[toxoplasmosis]]; and also fungi causing diseases such as [[ringworm]], [[candidiasis]] or [[histoplasmosis]]. However, other diseases such as [[influenza]], [[yellow fever]] or [[AIDS]] are caused by [[pathogenic viruses]], which are not usually classified as living organisms and are not, therefore, microorganisms by the strict definition. No clear examples of archaean pathogens are known,<ref>{{Cite journal |author=Eckburg, P. |author2=Lepp, P. |author3=Relman, D. |title=Archaea and Their Potential Role in Human Disease |journal=[[Infect Immun]] |volume=71 |issue=2 |pages=591–6 |year=2003 |pmid=12540534 | doi=10.1128/IAI.71.2.591-596.2003 |pmc=145348}}</ref> although a relationship has been proposed between the presence of some archaean methanogens and human [[periodontal disease]].<ref>{{Cite journal |author=Lepp, P. |author2=Brinig, M. |author3=Ouverney, C. |author4=Palm, K. |author5=Armitage, G. |author6=Relman, D. |title=Methanogenic Archaea and human periodontal disease | doi= 10.1073/pnas.0308766101 | journal=[[Proc Natl Acad Sci USA]] |volume=101 |issue=16 |pages=6176–81 |year=2004 |pmid=15067114 |pmc=395942|bibcode=2004PNAS..101.6176L |doi-access=free }}</ref> Numerous microbial pathogens are capable of sexual processes that appear to facilitate their survival in their infected host.<ref>{{cite journal | author = Bernstein H, Bernstein C, Michod RE | date = Jan 2018 | title = Sex in microbial pathogens | journal = Infect Genet Evol | volume = 57 | pages = 8–25 | doi = 10.1016/j.meegid.2017.10.024 | pmid = 29111273 | doi-access = free | bibcode = 2018InfGE..57....8B }}</ref>

* [[Staining (biology)|Staining]]