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设想土壤中存在不同类型的不完全反硝化细菌 ;这些细菌可以彼此配合 ,此菌产物作为彼菌的底物 ,共同完成完整的反硝化过程。该机制称之为“接力反硝化”机制 ,有别于传统的反硝化机制。本文为“接力反硝化”机制的存在提供部分证据。以土壤浸提液为培养基、N2 O为电子受体富集土壤微生物 ,获得了 1株仅完成NO-3 →NO-2 反应的细菌 (原始编号 2 1 6 9 2 )、1株仅完成NO-2 →N2 O反应的细菌 (原始编号 1 9 5 3)、1株仅完成NO-2 →N2 O→N2 反应的细菌 (原始编号 2 1 6 3 6 )。把菌株 2 1 6 9 2和 1 9 5 3两菌株以适当的数量比例混合于灭菌的土壤中 ,不添外来碳源 ,仅添加NO-3 ,厌气培养 1周后 ,测得土壤中剩余的NO-3 仅为原添加量的 39 4 %～ 5 3 0 % ,与此同时有 5 2 %～ 13 9%的NO-3 被还原成NO-2 ,有 2 8 6 %～ 30 8%以N2 O形态被回收 ,总回收率为 75 4 %～ 95 5 % ,说明两者可以相互配合 ,菌株 2 1 6 9 2的硝酸根还原产物可以被菌株 1 9 5 3用作底物 ,共同完成反硝化过程 ,从而支持我们设想的“接力反硝化”机制。
Imagine the presence of different types of imperfect denitrifying bacteria in the soil; these bacteria can work with each other and act as substrates for the bacterium to complete the complete denitrification process. The mechanism is called “relay denitrification” mechanism, different from the traditional denitrification mechanism. This article provides some evidence for the existence of “relay denitrification” mechanism. Taking soil extract as medium and N2 O as electron acceptor to enrich soil microorganism, one strain of bacteria that completed only NO-3 → NO-2 reaction (original number 2 1 6 9 2) was obtained, and only 1 strain was completed NO-2 → N2 O (original code: 1 9 5 3), and one bacterium (original code: 2 1 6 3 6) that only completed NO-2 → N2 O → N2 reaction. Strain 2 1 6 9 2 and 1 9 5 3 two strains were mixed in the appropriate amount of sterile soil, without adding carbon source, adding only NO-3, anaerobic culture for 1 week, measured in the soil The remaining NO-3 was only 39 4% ~ 53 0% of the original addition, while 52% ~ 13 9% of NO-3 was reduced to NO-2 with 286% ~ 30 8 % Was recovered in the form of N2 O with a total recoveries of 75 4% -95 5%, indicating that the two can cooperate with each other. The nitrate reduction product of strain 2 1 6 9 2 can be used as a substrate by strain 1 9 5 3, Work together to complete the denitrification process, thus supporting the “relay denitrification” mechanism that we envisioned.