Microbial art, agar art, or germ art is artwork created by culturing microorganisms in certain patterns. The microbes used can be bacteria, yeast fungi, or less commonly,

protist A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the exclu ...

s. The microbes can be chosen for their natural colours, or can be

engineered Engineering is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad range of more speciali ...

to express fluorescent proteins and viewed under ultraviolet light 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 culture microorganisms. Sometimes selective compounds are added to influence growth, such as antibiotics. Individual microorganisms placed on the plate wi ...

s are used as a canvas, while pigmented or

fluorescent Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, tha ...

bacteria and yeasts represent the paint. In order to preserve a piece of microbial art after a sufficient incubation, the microbe culture is sealed with epoxy. Microbe species can be chosen for their natural colours to form a palette for the artwork. 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 '' Bacillus ...

'' (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. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Esc ...

'' (colourless), '' Micrococcus luteus'' (yellow), '' Micrococcus roseus'' (pink), '' Proteus mirabilis'', '' Pseudomonas aeruginosa'' (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 gen ...

'' (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 infe ...

), ''

Serratia marcescens ''Serratia marcescens'' () is a species of 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 Padua, Italy.Serr ...

'' (pink or orange), '' Staphylococcus aureus'' (yellow), and ''

Vibrio fischeri ''Aliivibrio fischeri'' (also called ''Vibrio fischeri'') is a Gram-negative, rod-shaped bacterium found globally in marine environments. This species has bioluminescent properties, and is found predominantly in symbiosis with various marine an ...

'' (

bioluminescent Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some bi ...

). Yeast species – which are fungi – used include ''

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

'' (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 ''Aspergillus ochraceus'' is a mold species in the genus ''Aspergillus'' known to produce the toxin ochratoxin A, one of the most abundant food-contaminating mycotoxins, and citrinin. It also produces the dihydroisocoumarin mellein. It is a fila ...

'' (yellow), ''

Aureobasidium pullulans ''Aureobasidium pullulans'' is a ubiquitous and generalistic black, yeast-like fungus that can be found in different environments (e.g. soil, water, air and limestone). It is well known as a naturally occurring epiphyte or endophyte of a wide ra ...

'' (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'' sp. (whitish), ''

Cladosporium herbarum ''Cladosporium herbarum'' is a common fungus found worldwide in organic and inorganic matter. It is efficiently distributed in the air, where it exists as the most frequently occurring fungal species. It can grow over a wide range of temperature ...

'' (brown to black), ''

Cladosporium resinae ''Amorphotheca resinae'' is an ascomycete fungus of the family Amorphothecaceae which is known to thrive in environments containing alkanes (and water), like aviation fuel Aviation fuels are petroleum-based fuels, or petroleum and syntheti ...

'', '' 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 soil mi ...

'' sp., ''

Rhodotorula ''Rhodotorula'' is a genus of pigmented yeasts, part of the division Basidiomycota. It is readily identifiable by distinctive orange/red colonies when grown on Sabouraud's dextrose agar (SDA). This distinctive color is the result of pigments ...

'' 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 p ...

''.

Protist A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the exclu ...

species used include ''

Euglena gracilis ''Euglena gracilis'' is a freshwater species of single-celled alga 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 surface, allowing it to ...

'' ( photosynthetic, green) and ''

Physarum polycephalum ''Physarum polycephalum'', an 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 stage of the l ...

'' (yellow-green). A technique called "bacteriography" involves selectively killing certain areas of a bacterial culture with radiation, in order to produce artistic patterns. After incubation, the culture is sealed with

acrylic Acrylic may refer to: Chemicals and materials * Acrylic acid, the simplest acrylic compound * Acrylate polymer, a group of polymers (plastics) noted for transparency and elasticity * Acrylic resin, a group of related thermoplastic or thermosett ...

. The type of medium in the

agar plates An agar plate is a Petri dish that contains a growth medium solidified with agar, used to culture microorganisms. Sometimes selective compounds are added to influence growth, such as antibiotics. Individual microorganisms placed on the plate wil ...

is also important. Chromagar Candida is a differential medium that is 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, Bromthymol 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 solutions. It transitions from red to yellow at pH ...

turn yellow when the pH decreases, such as when bacteria consume sucrose. 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 what ...

, who is commonly credited with the discovery of penicillin 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. Some of his patients would even pay him in painting lessons. The biochemist

Roger Tsien Roger Yonchien Tsien (pronounced , "'' CHEN''"'';'' February 1, 1952 – August 24, 2016) was an American biochemist. He was a professor of chemistry and biochemistry at the University of California, San Diego and was awarded the Nobel Prize in ...

won the 2008 Nobel prize for chemistry for his contributions to knowledge of green fluorescent protein (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 w ...

hosts an annual contest for microbial art: Agar Art. 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 ''Deinococcus'' (from the el, δεινός, ''deinos'', "dreadful, strange" and κόκκος, ''kókkos'', "granule") is in the monotypic family Deinococcaceae, and one genus of three in the order Deinococcales of the bacterial phylum '' Deinoco ...

'' and '' Sphingomonas''. 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