Activity of nitrification inhibitors to several typical ammonia-oxidizing bacteria isolated recently, i. e. Nitrosococcus, Nitrosolobus, Nitrosomonas, Nitrosospira and Nitrosovibrio species was assayed using 2-amino-4-methyl-6-trichloromethyl-1,3,5-triazine (MAST), 2-amino- 4-tribromomethyl-6-trichloromethyl-1,3,5-triazine (Br-MAST), 2-chloro-6-trichloromethylpyridine (nitrapyrin) and others, and compared to confirm the adequate control of ammoniaoxidizing bacteria by the inhibitors. The order of activity of the inhibitors to 13 species of ammonia-oxidizing bacteria examined was approximately summarized as Br-MAST ≥ nitrapyrin ≥ MAST > other inhibitors. Two Nitrosomonas strains, N. europaea ATCC25978 and N. sp. B2, were extremely susceptible to Br-MAST, exhibiting a pI50 ≥ 6.40. These values are the position logarithms of the molar half-inhibition concentration. The 16S rRNA gene sequence similarity for the highly susceptible 4 strains of genus Nitrosomonas was 94% to 100% of Nitrosomonas europaea, although those of the less susceptible 3 strains of ammoniaoxidizing bacteria, Nitrosococcus oceanus C-107 ATCC19707, Nitrosolobus sp. PJA1 and Nitrosolobus multiformis ATCC25196, were 77.85, 91.53 and 90.29, respectively. However, no clear correlation has been found yet between pI50-values and percent similarity of 16S rRNA gene sequence among ammonia-oxidizing bacteria.
A Journal of Biosciences: Zeitschrift für Naturforschung C (ZNC) is an international scientific journal for the emerging field of natural and natural-like products. ZNC publishes original research on the isolation, bio-chemical synthesis and bioactivities of natural products, their biochemistry, pharmacology, biotechnology, and biological activity and innovative developed computational methods for predicting their structure and/or function.