Bacterial lawn is a term used by

microbiologist A microbiologist (from Ancient Greek, Greek ) is a scientist who studies microscopic life forms and processes. This includes study of the growth, interactions and characteristics of Microorganism, microscopic organisms such as bacteria, algae, f ...

s to describe the appearance of

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

colonies In modern parlance, a colony is a territory subject to a form of foreign rule. Though dominated by the foreign colonizers, colonies remain separate from the administration of the original country of the colonizers, the '' metropolitan state'' ...

when all the individual colonies on a

Petri dish A Petri dish (alternatively known as a Petri plate or cell-culture dish) is a shallow transparent lidded dish that biologists use to hold growth medium in which cells can be cultured,R. C. Dubey (2014): ''A Textbook Of Biotechnology For Class- ...

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 wil ...

merge to form a field or mat of bacteria. Bacterial lawns find use in screens for

antibiotic resistance Antimicrobial resistance (AMR) occurs when microbes evolve mechanisms that protect them from the effects of antimicrobials. All classes of microbes can evolve resistance. Fungi evolve antifungal resistance. Viruses evolve antiviral resistance. ...

and

bacteriophage A bacteriophage (), also known informally as a ''phage'' (), is a duplodnaviria virus that infects and replicates within bacteria and archaea. The term was derived from "bacteria" and the Greek φαγεῖν ('), meaning "to devour". Bacteri ...

titering. Bacterial lawns (often of ''

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.Serrati ...

'') are also used extensively when as an assay method when using

as tracers in studies of groundwater flow. Although occasionally used as a synonym for

biofilm A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular ...

, the term primarily applies to the simple, clonal, unstructured mats of organisms that typically only form on laboratory growth media. Biofilms—the aggregated form of

microorganism A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...

s most commonly found in

nature Nature, in the broadest sense, is the physics, physical world or universe. "Nature" can refer to the phenomenon, phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. ...

— are generally more complex and diverse and marked by larger quantities of extracellular structural matrix relative to the cellular

biomass Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms bi ...

Techniques

Bacterial lawns can be produced manually by evenly spreading a high amount of bacteria onto an agar plate using a sterile

cotton swab Cotton is a soft, fluffy Staple (textiles), staple fiber that grows in a wikt:boll, boll, or protective case, around the seeds of the cotton plants of the genus ''Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose ...

or a Drigalski spatula. Alternatively an automated machine can be used such as a

spiral plater A spiral plater is an instrument used to dispense a liquid sample onto a Petri dish in a spiral pattern. Commonly used as part of a CFU count procedure for the purpose of determining the number of microbes in the sample.J. E. Gilchrist, J. E. Cam ...

where the plate is rotated and the sample is spread evenly using an automated dispenser. They may also be produced using the "pour plate" technique in which a concentrated inoculum of the appropriate bacteria are mixed with melted agar and spread evenly over the surface of a Petri dish.

References

* {{DEFAULTSORT:Bacterial Lawn Bacteria Microbiology terms

Techniques

See also

References