Bioluminescence Bioluminescence is the ability of living things to emit light It is found in Many marine animals both invertebrate eg some cnidarians crustaceans squid and vertebrate some fishes ID: 579333
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Marine Biotechnology Lab
BioluminescenceSlide2
Bioluminescence is the ability of living things to emit light. Slide3
It is found in:
Many marine animals, both invertebrate (e.g., some cnidarians, crustaceans, squid) and vertebrate (some fishes
).Some
terrestrial animals (e.g., fireflies, some centipedes).
Some fungi and bacteria.Slide4
Bioluminescence in Marine AnimalsNinety percent of deep-sea marine life is estimated to produce bioluminescence.
The widespread
occurrence of luminescence among deep-sea animals reflects the perpetual darkness in which they live.
At least one fish has its luminescent organ
located at the tip of a protruding stalk and uses it as bait to lure prey within reach of its jaws.Slide5
When disturbed, one species of squid
emits a cloud of luminescent water instead of the ink that its shallow-water relatives use.Some
marine animals that live near the surface have luminescent organs on their underside. These probably make it more difficult for predators beneath them to see
them against the light background of the surface
In the case of fishes, the light is emitted by luminescent bacteria that grow in luminescent organs. Slide6
The photos show the flashlight fish, Photoblepharon
palpebratus, with the lid of its luminescent organ open (left) and closed (right).
The light is produced by continuously-emitting luminescent bacteria within the organs, but its display is controlled by the fish. Slide7
Camouflage
Attraction prey for feeding e.g. Luminous lure.Defense, Repulsion, expelling, or confusing a potential predator.
Communication (in the dark) for Mating or Schooling of fish.
Illumination.
Most marine animals appear to use their luminescent organs for such varied functions as :Slide8
Biotechnological ApplicationsBioluminescent organisms are a target for many areas of research. Luciferase
systems are widely used in the field of genetic engineering.
Some proposed applications of engineered bioluminescence include:
Glowing trees to line highways to save government electricity billsAgricultural
crops and domestic plants that luminesce when they need wateringNovelty pets that bioluminesce (rabbits, mice, fish etc.)Slide9
How does bioluminescence work?The group of chemicals responsible for light is known as
luciferins.
The enzyme behind
bioluminescence that catalyzes luciferin is luciferase
. Slide10
In bacteria, luciferase catalyzes the oxidation of reduced flavin
mononucleotide (FMNH2
) and a long-chain fatty aldehyde in the presence of molecular oxygen to yield FMN, carboxylate and blue light of 490nm.
The reaction is as follows:
FMNH
2
+ RCHO + O
2
----------- FMN + RCOOH + H2O + light (490 nm).
where R represents a long-chain alkyl group.Slide11Slide12
MaterialsSlide13
NaCl 8.88 gMgCl
2.6H2O 1.62 gMgSO4
.7H2O 24.6438 gKCl 0.238
Peptone 2 gGlycerol 1.2mlYeast extract 1.2g
Agar 6gDistilled water 400
mlCulture Media Recipe "seawater complete (SWC) medium"Slide14
Method
Measure out the materials in the above recipe to make 400 ml of agar medium
and place them in a 500 ml flask.Mix
the ingredients. To ensure complete dissolution.Bring to a gentle boil on a hotplate until all ingredients are dissolved
.Dispense into four 150 ml flasks (100 ml each
).Stopper the flasks with nonabsorbent cotton and aluminum foil.Slide15
Autoclave the agar at 121oC, 15
lbs pressure for 15 min.
While autoclaving, clean the working area inside the laminar airflow that you will be using.
Put all the materials you need including the medium in the laminar airflow and turn on UV lamp
.Allow the medium to cool to 55
oC.Slide16
Use sterile plates to prepare agar plates as you need them for culturing bacteria.
Work quickly, remove the cap of a flask, flame the mouth, and pour the liquid agar into a sterile petri dish while the cover is partially raised
.Swirl
the liquid so it covers the entire bottom surface.Allow to solidify.
Replace the cover.Slide17
Aseptically inoculate the center of the agar plates with a single
loopfull taken (transferred) from the fish surface and/or gills.
Use sterilized bent glass rod to spread the inoculum over the entire surface of the media.
Replace the lid of the dish.Label bottom of plates (not the top) along the edge.
Wrap the Parafilm around the edge of the Petri dish to slow evaporation
.Incubate for 1 to 2 days in an inverted position; observe the growth of luminescent microorganisms.Slide18
Bioluminescent AlgaeIn this experiment, you will
examine bioluminescence in dinoflagellates.Slide19
Procedure
Prepare a wet-mount slide of
dinoflagellates. To do so:a. Transfer a drop of dinoflagellates
to a slide.b. Cover the drop with a cover slip.
Place the slide on a compound light microscope, turn on the microscope light, and focus on low power. Observe organisms for a minute or two.
Without disturbing the slide, turn off the microscope light and the room lights. Leave both off for about two minutes.
While the lights are off, look through the eyepiece of the microscope. Watch the dark slide for a minute or two.
While observing through the eyepiece, gently tap the slide to disturb the organisms.