School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Bioresour Technol. 2010 Jul;101(14):5194-200. doi: 10.1016/j.biortech.2010.02.043. Epub 2010 Mar 4.
Strain HNR, isolated from a Membrane Bioreactor (MBR), demonstrates a surprising ability to convert ammonium to nitrogen gas under aerobic conditions while growing heterotrophically. On the basis of phylogenetic analysis of the 16S rRNA gene sequence, strain HNR was related to Acinetobacter calcoaceticus (98.9% identity). Nitrogen balance during heterotrophic growth with 120mg/l of NH(4)(+)-N showed that 40.2% of NH(4)(+)-N was in the form of N(2) and 52.1% was found in biomass. Only a trace production was either nitrite or nitrate. Further tests demonstrated that nitrite and nitrate were not reduced by strain HNR under aerobic conditions. Neither nitrate reductase (NR) nor nitrite reductase (NiR) activity was detectable in the aerobic reaction mixtures. However, a 0.051 U activity of hydroxylamine oxidase (HAO) was observed. The nitrogen removal was speculated to be via a hydroxylamine intermediate instead of nitrite, which was different from the conventional nitrogen removal pathway.
从膜生物反应器（MBR）中分离出的菌株 HNR，在好氧条件下以异养方式生长时，表现出将氨转化为氮气的惊人能力。根据 16S rRNA 基因序列的系统发育分析，菌株 HNR 与醋酸钙不动杆菌（98.9%的同源性）有关。在以 120mg/l 的 NH(4)(+)-N 进行异养生长时的氮平衡表明，40.2%的 NH(4)(+)-N 以 N(2)的形式存在，52.1%存在于生物量中。只有痕量的亚硝酸盐或硝酸盐生成。进一步的测试表明，在好氧条件下，菌株 HNR 不会还原亚硝酸盐和硝酸盐。在好氧反应混合物中检测不到硝酸盐还原酶 (NR) 或亚硝酸盐还原酶 (NiR) 活性。然而，观察到羟胺氧化酶 (HAO) 的 0.051 U 活性。氮的去除被推测是通过羟胺中间体而不是亚硝酸盐，这与传统的氮去除途径不同。
