Team:Copenhagen/Project/Cyanobacteria

Bioluminescence

Bioluminescence is light that is produced by a chemical reaction and then emitted from the living organism in which the reaction takes place.

One of the more known organisms to produce this kind of light are fireflies, but many other, such as bacteria, are able to emit light as well. Bioluminescence is used in nature for many different purposes. Some use it to scare of enemies, others to attract mates and still others use it as camouflage. Luciferase is the enzyme responsible for the chemical reaction that produces light. Luciferase catalyzes the oxidation of the compound luciferin which results in an unstable intermediate that will emit light as it decays to its ground state.

As in nature, bioluminescence can be used for many different purposes in biotechnology as well. A common use is different imaging methods and expression analyses.

A. fischeri are gram negative bacteria that can live in symbiosis with for example squid and thereby make them glow. The bacteria contain an operon which is a collection of genes that are all controlled by the same promoter and therefore expressed simultaneously. The Lux operon in A. fischeri contains the genes Lux A, Lux B, Lux C, Lux D and Lux E whose joint function is to produce the enzyme luciferase and regenerate the components necessary for the enzyme to work. The expression of the genes is controlled by a promotor that can be induced by many different stimulants for example a certain wavelength of light, a high colony concentration or the presence of a certain protein.

In our project the lux operon will be placed in the cyanobacteria PCC 7002 and a night induced promotor lrtA