Advanced Water Management Centre (AWMC), The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia.
Water Res. 2010 May;44(9):2901-9. doi: 10.1016/j.watres.2010.02.010. Epub 2010 Feb 13.
Nitrite/Free Nitrous Acid (FNA) has previously been shown to inhibit aerobic and anoxic phosphate uptake by polyphosphate accumulating organisms (PAOs). The inhibitory effect of FNA on the aerobic metabolism of Glycogen Accumulating Organisms (GAOs) is investigated. A culture highly enriched (92+/-3%) in Candidatus Competibacter phosphatis (hereafter called Competibacter) was used. The experimental data strongly suggest that FNA likely directly inhibits the growth of Competibacter, with 50% inhibition occurring at 1.5 x 10(-3)mgN-HNO(2)/L (equivalent to approximately 6.3 mgN-NO(2)(-)/L at pH 7.0). The inhibition is well described by an exponential function. The organisms ceased to grow at an FNA concentration of 7.1 x 10(-3) mgN-HNO(2)/L. At this FNA level, glycogen production, another anabolic process performed by GAOs in parallel to growth, decreased by 40%, while the consumption of polyhydroxyalkanoates (PHAs), the intracellular carbon and energy sources for GAOs, decreased by approximately 50%. FNA likely inhibited either or both of the PHA oxidation and glycogen production processes, but to a much less extent in comparison to the inhibition on growth. The comparison of these results with those previously reported on PAOs suggest that FNA has much stronger inhibitory effects on the aerobic metabolism of PAOs than on GAOs, and may thus provide a competitive advantage to GAOs over PAOs in enhanced biological phosphorus removal (EBPR) systems.
亚硝酸盐/游离亚硝酸（FNA）先前已被证明可抑制聚磷酸盐积累菌（PAOs）的好氧和缺氧磷吸收。本研究调查了 FNA 对糖原积累菌（GAOs）好氧代谢的抑制作用。使用高度富集（92+/-3%）的 Candidatus Competibacter phosphatis（以下简称 Competibacter）的培养物。实验数据强烈表明 FNA 可能直接抑制 Competibacter 的生长，50%的抑制发生在 1.5 x 10(-3)mgN-HNO(2)/L（相当于 pH 7.0 时约 6.3 mgN-NO(2)(-)/L）。抑制作用很好地用指数函数来描述。当 FNA 浓度达到 7.1 x 10(-3)mgN-HNO(2)/L 时，生物停止生长。在这个 FNA 水平下，糖原的产生，GAOs 与生长平行进行的另一种合成代谢过程，减少了 40%，而多羟基烷酸酯（PHAs）的消耗，GAOs 的细胞内碳和能源来源，减少了约 50%。FNA 可能抑制了 PHA 氧化和糖原生产过程中的一种或两种，但与生长抑制相比，程度要小得多。将这些结果与先前报道的 PAOs 进行比较表明，FNA 对 PAOs 的好氧代谢的抑制作用比 GAOs 强得多，因此在增强生物除磷（EBPR）系统中，FNA 可能为 GAOs 提供相对于 PAOs 的竞争优势。
