TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Composition: The composition is in a liquid, frozen, freeze-dried or powdered form. The composition is included in a polymer. The polymer is acrylamide, alginate and/or carrageenan. The composition comprises a concentrated bacterial strain that oxidizes ammonia to nitrite, where the 16S rDNA of the bacterial strain has a nucleotide sequence having at least 96% identity with the sequence comprising 1467, 1494 or 1491 bp. The composition further comprises a microorganism consisting of ammonia-oxidizing microorganisms, nitrite-oxidizing microorganisms, nitrate-reducing microorganisms and/or heterotrophic microorganisms.Preferred Method: Alleviating or preventing the accumulation of ammonia in a medium comprises:(1) providing a bacterial strain that oxidizes ammonia to nitrite; and(2) introducing into the medium an amount of the bacterial strain sufficient to alleviate or prevent the accumulation of ammonia in the medium.The ammonia is reduced by at least 30% when compared with a level of ammonia that would exist in the absence of the bacterial strain. The medium is an aquarium. The aquarium is a freshwater or seawater aquarium. Introducing into the medium an amount of the bacterial strain further comprises placing the bacterial strain into the medium on a rotating biological contactor or a biofilter. The bioremediation process that alleviates or prevents the accumulation of ammonia in a medium comprises:(1) providing a bacterial strain that oxidizes ammonia to nitrite; and(2) introducing into the medium an amount of the bacterial strain sufficient to remediate the medium.Detecting and determining the quantity of bacteria that oxidize ammonia to nitrite in a medium comprises:(1) providing a detectably labeled probe including a nucleotide sequence comprising 18 bp;(2) isolating total DNA from the medium;(3) exposing the isolated total DNA to the detectably labeled probe under conditions under which the probe hybridizes to only the nucleic acid of bacteria having 16S rDNA including the nucleotide sequence; and(4) detecting and measuring the amount of hybridized probe, where the presence of hybridized probe is indicative of the presence of bacteria that oxidize ammonia to nitrite and the amount of hybridized probe is indicative of the quantity of the bacteria that oxidize ammonia to nitrite in the medium.The medium includes a material consisting of aquarium gravel, filter sponges, filter floss or plastic filter media. The total DNA is isolated from the material. Providing a detectably labeled probe further comprises including the detectably labeled probe on a DNA chip. The method for detecting and determining the quantity of bacteria that oxidize ammonia to nitrite in a medium is an automated process. The automated process is DNA microarray, protein microarray, biosensor, bioprobe, capillary electrophoresis or real-time PCR.