Bacterial Bioluminescence

Bioluminescence• Phenomenon of production and emission of light by an

organism through chemical reaction.

• chemical energy Light energy

• Bioluminescent animals

Are mostly - marine

Very few - terrestrial

Examples Bioluminescent Organisms

Marine Terrestrial

Types of Bioluminescence

Bacterial Intrinsic

Bacterial Bioluminescence

1. Photobacterium luciferum

2. Vibrio fischerie / harveyi / phosphoreum

How do they look like?- Typically curved rods 1 to 3 microns long and motile by

flagella

Where are they found?- Can be found in Seawater (1 to 100 cells per ml), fish digestive tracts, and on the outside of decaying fish

How do they make light?• by a chemical reaction that consumes oxygen

• the reaction is catalyzed by an enzyme called luciferase

• Bioluminescence: Not found in freshwater organisms.

When do they make light?

-Light is only produced when the organisms are present at high cell densities

Photophors• Light producing organ

How do they get the bacteria?

- organ open to exterior (provide entrance for bacteria to enter)- potentially continuous luminescence

Bacterial Photophors• Squid Euprymna- squid hatches without bacteria; within

hours it is infected with natural populations of bacteria

Bacterial Photophors in Fish

Pinecone Fish Anglerfish flashlightfish

ponyfish

Benefits of Bioluminescence

Some predators can lure prey by mimicking signals of prey. Other predators dangle a lure to attract prey.

Finding or attracting prey

Defense against predators

• mid-water squid releases a bioluminescent cloud to startle and confuse predators

Communication / Mating

squids- looking for mates

Attract opposite sex.

Other bioluminescent animals

pterapods