Bioluminescence

Bioluminescence ( gr βιός bios " life" and the Latin lumen " light " ) is in biology refers to the ability of living organisms to produce light themselves or with the help of symbionts. The generation of light found in higher organisms often organized in special light organs rather than in eukaryotic unicellular organisms in specific organelles and bacteria in the cytoplasm. It is based on chemical processes in which the energy released is emitted in the form of light, so it is a chemiluminescence. A distinction is made in bioluminescence between primary and secondary lights. The rule represents the primary lights, in which an animal to be luminaire is capable. Arises the lights instead by symbiotic bacteria, as known eg from fish, one speaks of the secondary lights.

• 3.1 symbioses
• 3.2 luciferin / luciferase
• 3.3 aequorin / coelenterazine / coelenteramide
• 3.4 Foxfire bioluminescence

Biological Function

Bioluminescence may have different functions:

• Attracting prey or partners
• Communication
• Warning or Drohfunktion
• Quenching or deflection function
• Camouflage by matching its own light to match the ambient light

Dissemination

In almost all kingdoms of organisms there is not bioluminescent species, but among higher plants and terrestrial vertebrates.

Animals

Insects with bioluminescence include fireflies ( fireflies; Lampyridae ) and luminous beetles ( genera Cucujo and Pyrophorus ). There are also glowing Collembola ( springtails ).

Particularly widespread luminescence is under marine life, especially in the deep sea (up to 90 percent of deep-sea organisms ), but also in coastal waters ( about five percent). Various cephalopods like the vampire squid ( Vampyroteuthis infernalis ), the Aladdin Lamp ( Lycoteuthis ) and other squid ( Teuthida ), light crabs ( krill, Euphausiacea ), luminescent jellyfish ( Pelagia noctiluca, Aequorea victoria, Periphylla periphylla ), polychaetes as Eusyllis blomstrandi in Helgoland rocky intertidal (Helgoland ), which hidden in the sand living Chaetopterus variopedatus and the free-floating Tomopteris helgolandica, corals such as ( Renilla reniformis ) and various deep-sea fish. Among the nudibranchs ( Nudibranchia ), sea-living slugs, there are also several bioluminescent species, such as Plocamopherus imperialis and Phylliroe bucephalum.

Mushrooms

Of the more than 100,000 species of fungi studied are only 71 bioluminescent. These include honey fungus ( Armillaria sp., Armillaria mellea ), the Shining olive tree fungus ( Omphalotus olearius ) and some species of the genera Panellus ( Panellus stipticus ), Pleurotus ( Pleurotus japonicus ) and Mycena ( Mycena citricolor, Mycena lux- coeli ).

The bioluminescence evolved into four lineages. It could be shown that the Biolumineszenzerscheinungen based in all four lineages on the same foundations.

Protozoa

The so-called phosphorescence caused by plankton, for example, from single-celled dinoflagellates ( noctiluca miliaris ) responsive to flow variations with the emission of light. Meeresleuchten can be observed in many coastal areas.

Bacteria

There are some free-living luminous bacteria in seawater, which are also found on foods such as fish, meat and eggs. These include, for example, Vibrio fischeri and Photobacterium. Vibrio fischeri proliferates on dead saltwater fish and can be observed easily, if you for some time kept a dead, fresh salted herring cool, then the lights in the dark places.

There are also symbiotic luminous bacteria, which occur in particular organs of marine animals; especially anglers and lantern fish live in symbiosis with luminous bacteria.

Generation

There are two forms of bioluminescence distinguished: the primary and secondary lights. As the primary lights is referred to when the organism produces the luminescence itself. As a secondary indication, however, is called when an organism living in symbiosis with other organisms (eg with luminescent bacteria ), which have the possibility to primary lights.

Symbioses

Symbioses of animals with luminescent bacteria occur. Here the bacteria are supplied by their hosts with nutrients and oxygen, and often live in special skin bags or parts of the body. One example is the deep sea angler fish.

Luciferin / luciferase

A frequently used bioluminescent chemical reaction is the exergonic oxidation of luciferins with molecular oxygen (O2), catalyzed by enzymes of the luciferases. This produces dioxetanes or dioxetanones which decompose to give off carbon dioxide and releasing the stored energy in the form of light.

Both the luciferins and the luciferases are art- or group-specific, so characteristic for each group of organisms. The luciferases are evident in the evolution of other enzymes, the oxygenases, emerged. In changing, usually the separation of sub-groups of the luciferin, creates energy that is emitted as a photon.

Aequorin / coelenterazine / coelenteramide

Another type of light production, namely by photoproteins uses the jellyfish Aequorea victoria. This coelenterate ( Coelenterate ) used aequorin, a Ca2 -dependent primary photoprotein. Because it is not chemically transformed in the course of the reaction as other luciferins, but passes back to its initial state after the emission of light, it is unlimited recyclable. The blue - green glow of this jellyfish is caused by the combination of aequorin with the green fluorescent protein (GFP).

Foxfire bioluminescence

Fungi use Foxfire bioluminescence, wherein the enzyme superoxide dismutase ( SOD) results in the production of bioluminescence.

Application

Bioluminescence is not only for basic research of interest. For some time, various technical applications of bioluminescence are routinely used. As bioluminescence is applied for example as a low-risk marker method in molecular biology, the method has largely been replaced radiolabelling together with fluorescent labels. Also known as detection method in ecotoxicology bioluminescence is used for the detection and quantification of toxins. The use of dinoflagellates in the flow of research for the detection of turbulence is discussed. Some researchers announce already self-luminous displays to based on bioluminescence.

1999 British newspapers reported - and subsequently the media in other countries - about alleged work on self-luminous Christmas trees. This has, however, never really existed.