The mutation arises due to a defect in the gene that constantly codes for the enzyme. A gene that is producing a product without any inhibition is said to have constitutive activity. This particular mutant form is used to isolate and purify the aforementioned enzyme.Strain OP50 of Escherichia coli is used for maintenance of Caenorhabditis elegans cultures. Strain JM109 is a mutant form of E. coli that is recA and endA deficient. The strain can be utilized for blue/white screening when the cells carry the fertility factor episome. Lack of recA decreases the possibility of unwanted restriction of the DNA of interest and lack of endA inhibit plasmid DNA decomposition. Thus, JM109 is useful for cloning and expression systems. Model organism
E. coli is frequently used as a model organism in microbiology studies. Cultivated strains (e.g. E. coli K12) are well-adapted to the laboratory environment, and, unlike wild-type strains, have lost their ability to thrive in the intestine. Many laboratory strains lose their ability to form biofilms. These features protect wild-type strains from antibodies and other chemical attacks, but require a large expenditure of energy and material resources. E. coli is often used as a representative microorganism in the research of novel water treatment and sterilisation methods, including photocatalysis.
Less or LESS may refer to: fewer than,: not as much. Computing
less (Unix), a Unix utility program
Less (stylesheet language), a dynamic stylesheet language
Large-Scale Scrum (LeSS), a product development framework that extends Scrum

Other uses
-less, a privative suffix in English
Lunar Escape Systems, a series of proposed emergency spacecraft for the Apollo Program
Christian Friedrich Lessing (1809–1862), (author abbreviation Less.) for German botanist
Less (novel), a 2017 novel by Andrew Sean Greer

See also
Fewer versus less
Less is more (disambiguation)
All pages with titles beginning with Less
All pages with titles containing Less