In bacteriology, minicells are bacterial cells that are smaller than usual. The first minicells reported were from a
strain of ''
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 ...
'' that had a mutation in the
Min System
The Min System is a mechanism composed of three proteins MinC, MinD, and MinE used by ''E. coli'' as a means of properly localizing the septum prior to cell division. Each component participates in generating a dynamic oscillation of FtsZ pro ...
that lead to mis-localization of the
septum
In biology, a septum (Latin for ''something that encloses''; plural septa) is a wall, dividing a cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate.
Examples
Human anatomy
* Interat ...
during cell division and the production of cells of random sizes.
Generation of minicells
The first report of minicells in the scientific literature dates to 1930., but the first use of the name "minicell" dates to 1967
Minicells of a variety of
gram negative
The gram (originally gramme; SI unit symbol g) is a unit of mass in the International System of Units (SI) equal to one one thousandth of a kilogram.
Originally defined as of 1795 as "the absolute weight of a volume of pure water equal to t ...
and
gram positive
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall.
Gram-positive bact ...
bacteria, including ''
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 ...
'' and ''
Salmonella enterica
''Salmonella enterica'' (formerly ''Salmonella choleraesuis'') is a rod-headed, flagellate, facultative anaerobic, Gram-negative bacterium and a species of the genus '' Salmonella''. A number of its serovars are serious human pathogens.
Epidem ...
'', have been reported, but in principle, minicells could be generated for any bacterial species that can be genetically edited. Minicells can not reproduce because they do not contain a full copy of the genome.
Normal role of minicells in bacteriology
Scientists hypothesize that minicells are produced by normal bacteria in times of stress so that damaged areas of the cell can be expelled.
Applications of minicells
Minicells have been extensively used to study
ultrastructure
Ultrastructure (or ultra-structure) is the architecture of cells and biomaterials that is visible at higher magnifications than found on a standard optical light microscope. This traditionally meant the resolution and magnification range of a con ...
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 am ...
using
electron cryotomography (cryoET). Minicells are ideal for cryoET because they are small enough for the electron beam to penetrate in
transmission electron microscopy
Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a gr ...
.
Bacterial minicells are being developed as a drug delivery system. Minicells could be used to deliver genetic material to eukaryotic cells for gene editing. They are also being investigated for vaccine development.
References
{{Reflist
Further reading
Minicells, at openwetware.org
Bacteriology