Many heterotrophic nitrifiers can utilize neither nitrate nor nitrite
as the nitrogen source for growth, such as Alcaligenes faecalis
No. 4 (6), Alcaligenes faecalis strain NR (31) and Acinetobacter calcoaceticus
HNR (7). For Acinetobacter calcoaceticus HNR, nitrite and
nitrate could not be utilized even induced by ammonium. Pseudomonas
sp. ASM-2-3 could remove 225.8 mg NO3
-N by 12 h without
the accumulation of nitrite, but its ability to remove nitrite was not
mentioned (34). Nitrite has obvious inhibitory effects on most nitrifying
and denitrifying bacteria (35). Glass et al. (36) found that
30 mg/L of NO2
-N could inhibit denitrification at pH value of 6.
Abeling and Seyfried (37) reported that the toxic threshold of nitrite
to denitrifying bacteriawas 0.13 mg/L. Therefore, the denitrification
capability using nitrite as substrate is very important for nitrogen
removal and nitrite pollution control