Disease relevance of nirS

• Presence of two different active nirS nitrite reductase genes in a denitrifying Thauera sp. from a high-nitrate-removal-rate reactor [1].
• The sequence was similar to the nirS sequences of Thauera mechernichensis (83% similarity) and Azoarcus tolulyticus (83% similarity) both of which belong to the Rhodocyclus group [2].

High impact information on nirS

• The nirS nitrite reductase genes were studied in two strains (strains 27 and 28) isolated from two denitrifying reactors and characterized as Thauera according to their 16S rRNA gene sequences [1].
• One of the nirS clones was approximately 70% of all nirS clones in anaerobic/aerobic (existing oxygen and nitrate) cycle operation in which a large amount of anoxic phosphate uptake was observed [2].
• Nitrite reductase gene (nirS) fragments in the activated sludge obtained from a sequencing batch reactor (SBR) under anaerobic-aerobic condition were cloned and classified by restriction fragment length polymorphism (RFLP) analysis, and representative fragments were sequenced [2].

Associations of nirS with chemical compounds

• All strains appeared to have heme nitrite reductase since their DNA hybridized to the heme (nirS) but not to the Cu (nirU) genes [3].
• Although the activated sludge samples analyzed might contain bacteria that did not accumulate polyphosphate, it was likely that this nirS fragment sequence was that from denitrifying polyphosphate-accumulating organisms (DNPAOs) which can utilize both oxygen and nitrate as electron acceptors [2].

References