Microbial art, agar art, or germ art is artwork created by culturing

microorganisms A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from antiquity, with an early attestation in ...

in certain patterns. The microbes used can be

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...

fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

, or less commonly,

protist A protist ( ) or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus. Protists do not form a natural group, or clade, but are a paraphyletic grouping of all descendants of the last eukaryotic common ancest ...

s. The microbes can be chosen for their natural colours or engineered to express fluorescent proteins and viewed under

ultraviolet light Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of th ...

to make them fluoresce in colour.

Methods

Agar plate An agar plate is a Petri dish that contains a growth medium solidified with agar, used to Microbiological culture, culture microorganisms. Sometimes selective compounds are added to influence growth, such as antibiotics. Individual microorganism ...

s are used as a canvas, while pigmented or

fluorescent Fluorescence is one of two kinds of photoluminescence, the emission of light by a substance that has absorbed light or other electromagnetic radiation. When exposed to ultraviolet radiation, many substances will glow (fluoresce) with color ...

and

s represent paint. In order to preserve a piece of microbial art after a sufficient incubation, the microbe culture is sealed with

epoxy Epoxy is the family of basic components or Curing (chemistry), cured end products of epoxy Resin, resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide fun ...

. Microbe species can be artistically chosen for their natural colours to form a palette. Suitable species of bacteria (with their colours) include ''

Bacillus subtilis ''Bacillus subtilis'' (), known also as the hay bacillus or grass bacillus, is a gram-positive, catalase-positive bacterium, found in soil and the gastrointestinal tract of ruminants, humans and marine sponges. As a member of the genus ''Bacill ...

'' (cream to brown), ''

Chromobacterium violaceum ''Chromobacterium violaceum'' is a Gram-negative, facultative anaerobic, non-sporing coccobacillus. It is motile with the help of a single flagellum which is located at the pole of the coccobacillus. Usually, there are one or two more lateral ...

'' (violet), ''

Escherichia coli ''Escherichia coli'' ( )Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Escherichia'' that is commonly fo ...

'' (colourless), ''

Micrococcus luteus ''Micrococcus luteus'' is a Gram-positive to Gram-variable, nonmotile, tetrad-arranging, pigmented, saprotrophic coccus bacterium in the family Micrococcaceae. It is urease and catalase positive. An obligate aerobe, ''M. luteus'' is found in soi ...

'' (yellow), '' Micrococcus roseus'' (pink), ''

Proteus mirabilis ''Proteus mirabilis'' is a Gram-negative, facultatively Anaerobic organism, anaerobic, rod-shaped bacterium. It shows swarming motility and urease activity. ''P. mirabilis'' causes 90% of all ''Proteus (bacterium), Proteus'' infections in human ...

'', ''

Pseudomonas aeruginosa ''Pseudomonas aeruginosa'' is a common Bacterial capsule, encapsulated, Gram-negative bacteria, Gram-negative, Aerobic organism, aerobic–facultative anaerobe, facultatively anaerobic, Bacillus (shape), rod-shaped bacteria, bacterium that can c ...

'' (brown), ''

Pseudomonas fluorescens ''Pseudomonas fluorescens'' is a common Gram-negative, rod-shaped bacterium. It belongs to the ''Pseudomonas'' genus; 16S rRNA analysis as well as phylogenomic analysis has placed ''P. fluorescens'' in the ''P. fluorescens'' group within the genu ...

'' (naturally blue-green

with

pyoverdine Pyoverdines (alternatively, and less commonly, spelled as pyoverdins) are fluorescent siderophores produced by certain pseudomonads. Pyoverdines are important virulence factors, and are required for pathogenesis in many biological models of infec ...

), ''

Serratia marcescens ''Serratia marcescens'' () is a species of bacillus (shape), rod-shaped, Gram-negative bacteria in the family Yersiniaceae. It is a facultative anaerobe and an opportunistic pathogen in humans. It was discovered in 1819 by Bartolomeo Bizio in Pa ...

'' (pink or orange), ''

Staphylococcus aureus ''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often posi ...

'' (yellow), and '' Vibrio fischeri'' (

bioluminescent Bioluminescence is the emission of light during a chemiluminescence reaction by living organisms. Bioluminescence occurs in multifarious organisms ranging from marine vertebrates and invertebrates, as well as in some fungi, microorganisms inc ...

Yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...

species – which are

– used in microbial art include ''

Saccharomyces cerevisiae ''Saccharomyces cerevisiae'' () (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungal microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have be ...

'' (yellow–white) ''

Aspergillus flavus ''Aspergillus flavus'' is a saprotrophic and pathogenic fungus with a cosmopolitan distribution. It is best known for its colonization of cereal grains, legumes, and tree nuts. Postharvest rot typically develops during harvest, storage, and/or ...

'' (yellow–green spores), '' Aspergillus ochraceus'' (yellow), '' Aureobasidium pullulans'' (black), ''

Candida albicans ''Candida albicans'' is an opportunistic pathogenic yeast that is a common member of the human gut flora. It can also survive outside the human body. It is detected in the gastrointestinal tract and mouth in 40–60% of healthy adults. It is usu ...

'' (whitish buff), ''

Candida sake Candida, or Cándida (Spanish), may refer to: Biology and medicine * ''Candida'' (fungus), a genus of yeasts ** Candidiasis, an infection by ''Candida'' organisms * Malvasia Candida, a variety of grape Places * Candida, Campania, a ''comu ...

'', ''

Candida Candida, or Cándida (Spanish), may refer to: Biology and medicine * ''Candida'' (fungus), a genus of yeasts ** Candidiasis, an infection by ''Candida'' organisms * Malvasia Candida, a variety of grape Places * Candida, Campania, a ''comu ...

'' sp. (whitish), '' Cladosporium herbarum'' (brown to black), '' Cladosporium resinae'', '' Epicoccum nigrum'' (yellow, orange, red, brown, and black), ''

Fusarium ''Fusarium'' (; ) is a large genus of filamentous fungi, part of a group often referred to as hyphomycetes, widely distributed in soil and associated with plants. Most species are harmless saprobes, and are relatively abundant members of the s ...

'' sp., ''

Rhodotorula ''Rhodotorula'' is a genus of fungi in the class (biology), class Microbotryomycetes. Most species are known in their yeast states which produce orange to red colony (biology), colonies when grown on Sabouraud agar, Sabouraud's dextrose agar (SD ...

'' sp., and ''

Scopulariopsis brevicaulis ''Microascus brevicaulis'' is a microfungus in the Ascomycota. It is the teleomorph form of ''Scopulariopsis brevicaulis.'' ''Microascus brevicaulis'' occurs world-wide as a saprotroph in soil, a common agent of biodeterioration, an irregular pl ...

''.

Protist A protist ( ) or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus. Protists do not form a natural group, or clade, but are a paraphyletic grouping of all descendants of the last eukaryotic common ancest ...

species used in microbial art include ''

Euglena gracilis ''Euglena gracilis'' is a freshwater species of euglenid, a microscopic type of algae, in the genus ''Euglena''. It has secondary chloroplasts, and is a mixotroph able to feed by photosynthesis or phagocytosis. It has a highly flexible cell surf ...

'' (

photosynthetic Photosynthesis ( ) is a Biological system, system of biological processes by which Photoautotrophism, photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical ener ...

, green) and ''

Physarum polycephalum ''Physarum polycephalum'', an Multinucleate, acellular slime mold or myxomycete popularly known as "the blob", is a protist with diverse cellular forms and broad geographic distribution. The “acellular” moniker derives from the plasmodial s ...

'' (yellow–green). A technique called "bacteriography" involves selectively killing certain areas of a bacterial culture with

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or a material medium. This includes: * ''electromagnetic radiation'' consisting of photons, such as radio waves, microwaves, infr ...

in order to produce artistic patterns. After incubation, the culture is sealed with acrylic. The type of medium in the agar plates is also important. Chromagar Candida is a differential medium used to identify different ''Candida'' species. When grown on this medium, '' C. albicans'' is light green, ''C. tropicalis'' is steel blue with purple around the edges, and ''C. krusei'' is rose pink with white around the edges. However, using a different medium, ''C. tropicalis'' has maroon colonies. The color of the medium itself can also be changed using microbes. In TCBS agar, Bromothymol Blue and

Thymol Blue Thymol blue (thymolsulfonephthalein) is a brownish-green or reddish-brown crystalline powder that is used as a pH indicator. It is insoluble in water but soluble in alcohol and dilute alkali In chemistry, an alkali (; from the Arabic word , ...

turn yellow when pH decreases, such as when

consume

sucrose Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula . For human consumption, sucrose is extracted and refined ...

. In this way, the background color of the medium can be changed from dark green to light yellow.

Artists

Alexander Fleming Sir Alexander Fleming (6 August 1881 – 11 March 1955) was a Scottish physician and microbiologist, best known for discovering the world's first broadly effective antibiotic substance, which he named penicillin. His discovery in 1928 of wha ...

, who is commonly credited with the discovery of

penicillin Penicillins (P, PCN or PEN) are a group of beta-lactam antibiotic, β-lactam antibiotics originally obtained from ''Penicillium'' Mold (fungus), moulds, principally ''Penicillium chrysogenum, P. chrysogenum'' and ''Penicillium rubens, P. ru ...

in 1928, was known for creating germ paintings. Throughout his career, Fleming’s paintings became more colorful as he came to know more microbial species. He would incorporate them into his paintings of ballerinas, families, and other images. The biochemist Roger Tsien won the 2008

Nobel Prize in Chemistry The Nobel Prize in Chemistry () is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outst ...

for his contributions to knowledge of

green fluorescent protein The green fluorescent protein (GFP) is a protein that exhibits green fluorescence when exposed to light in the blue to ultraviolet range. The label ''GFP'' traditionally refers to the protein first isolated from the jellyfish ''Aequorea victo ...

(GFP) that has been used to create art-like works.

Agar Art Competition

The

American Society for Microbiology The American Society for Microbiology (ASM), originally the Society of American Bacteriologists, is a professional organization for scientists who study viruses, bacteria, fungi, algae, and protozoa as well as other aspects of microbiology. It wa ...

hosts an annual contest for microbial art: the Agar Art Contest. The contest was organized after a picture from a Christmas tree, made by Rositsa Tashkova, went viral in 2014. The 2015 edition covered 85 submissions, of which microbial art created by Mehmet Berkmen and Maria Peñil called ''Neurons'' won first place. The artwork used yellow '' Nesterenkonia'' and orange '' Deinococcus'' and ''

Sphingomonas ''Sphingomonas'' was defined in 1990 as a group of Gram-negative, rod-shaped, chemoheterotrophic, strictly Aerobic organism, aerobic bacteria. They possess ubiquinone 10 as their major Electron transport chain#Quinone carriers, respiratory quinon ...

''. In 2020, the ASM received over 200 submissions, and awarded first place to Joanne Dungo for her multi-plate creation titled "The Gardener."''American society for microbiology agar art''. (n.d.). American Society for Microbiology. Retrieved March 14, 2021, from https://asm.org/Events/ASM-Agar-Art-Contest/2020-Winners .

Notes

References

External links