Studies on the biochemical mechanism of N_2O generation by marine nitrifying bacterium

从海洋氨氧化细菌(AOB)菌株NS58中分离纯化了羟胺氧化还原酶(HAO)。用纯化的酶进行体外实验证明，HAO反应副产物N2O的产生是正确的。还揭示了HAO反应生成的N2O的独特同位素性质。利用该重组酶对参与硝化反硝化途径(AOB的另一种N2O生成机制)的亚硝酸还原酶的分子和酶特性进行了研究。

Hydroxylamine oxidoreductase (HAO) was purified from marine ammonia-oxidizing bacterium (AOB) strain NS58. Generation of N_2O as a by-product of HAO reaction was evidenced by in vitro experiment using the purified enzyme. Unique isotopic property of the N_2O generated by HAO reaction was also revealed. Molecular and enzymatic features of nitrite reductase, that was involved in the nitrifier denitrification pathway (another N_2O generation mechanism in AOB), was investigated using the recombinant enzyme.