Make an overview of the effects of ammonia and urease on the growth of seafood.

Assignment: Make an overview of the effects of ammonia and urease on the growth of seafood.
make an overview the (potential) effects of urease inhibition in fish farming.

Ammonia plays a crucial role in the seafood industry.
It is essential for growth of water animals (Fish, shrimp etc), however
– It can be a toxic component (intrinsic by overfeeding and extrinsic by a too high concentration of ammonia in the water).
– It can be a seafood (food) spoilage component

The mechanism of toxicity is that the ureum in the intestines are converted by bacterial ureases into ammonia. This transfers to the blood and the liver has to work hard to convert the ammonia back to urea. Too high levels of ammonia are know to be highly toxic for fish. If one feeds more than in a natural situation, a lot of ammonia is formed in the intestines, intoxicating the fish.

Related topic:
-Seafood suffers often from a human pathogen: A  bacterium from the Vibrio species.
-Urease is an enzyme which converts urea into ammonia.
-Urease is produced by these Vibrio species

– Finding: If one can inhibit the enzym urease, several effects are seen:
– Faster growth of (especially salt water) fish.
– Post-harvest: The fishy smell of fish is not forming.

We are interested in three major aspects to learn which effect are scientifically expected when we would have a specific inhibitor towards the enzyme urease.
a. Growth:
– Is a growth acceleration described when the enzym urease is inhibited. If yes why? What is the scientific explanation?
(other way of looking at it: can urease inhibition prevent ammonia intoxication?)
– Is a difference in growth acceleration between the salt water salmon and the sweat water trout or Tilapia described when  urease inhibition is applied?

b: Food spoilage.
– Please describe the reason for the fishy smell and described (expected) effects when a urease inhibitor is used.
Please put direct and indirect evidence in a separate paragraph.
Example indirect evidence: heating destroys urease and gives measurable effects; however it does more than that.. so the effect is  not directly attributable to urease, it is correlated. Antibiotic treatment is also an indirect effect, however if one proves that the result is achieved because of killing urease producing bacteria it is still correlated however with a high(er) degree of certainty that the effect is urease directed.
Example direct: if a chemical urease inhibitor is used which gives the result. Note: The chemical inhibitor NBPT is tried on fish, most effects are quite detrimental. Are there positive effects described?

c. The (expected) effect of urease inhibitors on Vibrio. (life fish and postharvest).
– please describe the Vibrio problem is seafood  (Salmon, shrimp, Mollusk):
Post harvest: Fishy smell development.
Pre en post harvest : human pathogen
– please describe the described effects when urease-inhibitor would be used. (will it kill, will it stop the growth; what will it do with the smell)