The oxidation of NH4+ by Nitrosomonas europaea was insensitive to 10 mM NaClO3 (sodium chlorate) but was strongly inhibited by NaClO2 (sodium chlorite; Ki, 2 μM). The oxidation of NO2? by Nitrobacter winogradskyi was inhibited by both ClO3? and ClO2? (Ki for ClO2?, 100 μM). N. winogradskyi reduced ClO3? to ClO2? under both aerobic and anaerobic conditions, and as much as 0.25 mM ClO2? was detected in the culture filtrate. In mixed N. europaea-N. winogradskyi cell suspensions, the oxidation of both NH4+ and NO2? was inhibited in the presence of 10 mM ClO3? after a 2-h lag period, despite the fact that, under these conditions, ClO2? was not detected in the filtrate. The data are consistent with the hypothesis that, in mixed culture, NH4+ oxidation is inhibited by ClO2? produced by reduction of ClO3? by the NO2? oxidizer. The use of ClO3? inhibition of NO2? oxidation in assays of nitrification by mixed populations necessitates cautious interpretation unless it can be shown that the oxidation of NH4+ is not affected.
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机译：欧洲亚硝化单胞菌对NH4 +的氧化对10 mM NaClO3（氯酸钠）不敏感，但被NaClO2（亚氯酸钠; Ki，2μM）强烈抑制。 NO2的氧化？硝酸盐菌被二氧化氯抑制？和二氧化氯？ （对于ClO 2而言，Ki为100μM）。 N. winogradskyi还原了ClO3？到ClO2？在有氧和厌氧条件下，以及高达0.25 mM的ClO2？在培养滤液中检测到。在混合欧洲猪笼草中。 winogradskyi细胞悬浮液，NH4 +和NO2均被氧化？ 10 mM ClO3存在时被抑制吗？经过2小时的延迟期后，尽管在这些条件下ClO2滤液中未检测到。数据与以下假设相符：在混合培养中，NH4 +的氧化被ClO2抑制。还原ClO3产生的？靠NO2吗？氧化剂。使用ClO3？抑制NO2？混合种群硝化分析中的氧化需要谨慎解释，除非可以证明NH4 +的氧化不受影响。
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