NOVELTY - An isolated bacterial strain (I) for oxidizing nitrite to nitrate, comprising a base pair sequence that has 96% or more sequence identity to a fully defined 1495 (SEQ ID No. 1), 1450 (SEQ ID No. 2), 1445 (SEQ ID No. 3), 1450 (SEQ ID No. 4), 1473 (SEQ ID No. 5), 1473 (SEQ ID No. 6), 1480 (SEQ ID No. 7), or 1490 (SEQ ID No. 8) base pair sequence given in the specification, is new.    USE - (I) is useful in a bioremediation process that alleviates or prevents accumulation of nitrite in a medium e.g. saltwater aquarium, freshwater aquarium, wastewater, or liquid in an aquaculture facility. (IIb) is useful for alleviating or preventing the accumulation of nitrite in a medium. (III) is useful for detecting and determining the quantity of bacteria that oxidize nitrite to nitrate in a medium (claimed).    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a biologically pure culture of (I);    (2) a composition (II) comprising:    (a) (I); or    (b) two or more of (I);    (3) an isolated nucleic acid comprising a base pair sequence that has 96% or more sequence identity to SEQ ID No. 1-8;    (4) an oligonucleotide probe (III) comprising:    (a) a fully defined 20 (SEQ ID No. 14), 22 (SEQ ID No. 15), 22 (SEQ ID No. 16), 18 (SEQ ID No. 17) or 21 (SEQ ID No. 18) base pair sequence given in the specification or (b) a base pair sequence having 96% or more sequence identity to SEQ ID No. 14-18, where (III) hybridizes to a nucleic acid of bacteria having 16S rDNA that has a base pair sequence with 96% or more sequence identity to SEQ ID No. 1-8;    (5) a PCR primer comprising a fully defined 17 (SEQ ID No. 19), 16 (SEQ ID No. 20), 21 (SEQ ID No. 21) or 20 (SEQ ID No. 22) base pair sequence given in the specification;    (6) a DNA chip comprising a solid substrate and (IIIa) configured upon the solid substrate; and    (7) a composition comprising (I) and ammonia-oxidizing bacteria, present in an approximately 1:3 ratio.    DESCRIPTION OF DRAWING(S) - The figure is a graph for representing the mean nitrite concentration trends for a bacterial additive test for assessing the viability of saltwater bacterial strains.