State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia.
Environ Sci Technol. 2020 Dec 1;54(23):15414-15423. doi: 10.1021/acs.est.0c04192. Epub 2020 Nov 12.
Nitrite oxidation is the primary pathway that generates nitrate in engineered systems. However, little is known about the role of a novel nitrite-oxidizing bacteria (NOB) genus Nitrotoga in activated sludge systems. To elucidate key factors that impact NOB community composition, laboratory-scale sequencing batch reactors (SBRs) were designed and operated under the same conditions as real wastewater treatment plants to achieve considerable nitrogen removal and similar community; then, different conditions including temperature (T), dissolved oxygen (DO), free nitrous acid (FNA), and free ammonia (FA) were applied. The 16S rRNA gene-based PCR and sequence analysis illustrated that . Nitrotoga were abundant even at ambient temperature, thus further challenging the previous conception of them being solely cold-adapted. . Nitrotoga are less competitive than during oxygen deficiency, indicating its lower affinity to dissolved oxygen. . Nitrotoga are the dominant nitrite oxidizers under regular exposure to FNA and FA due to their relatively higher resistance than other NOB toward these two effective biocides. Therefore, this study demonstrates that . Nitrotoga can play an important role in biological nitrogen removal and also highlights the need for multiple strategies for NOB suppression for the next-generation, shortcut nitrogen removal.
亚硝酸盐氧化是工程系统中生成硝酸盐的主要途径。然而，人们对新型亚硝酸盐氧化菌（NOB）属 Nitrotoga 在活性污泥系统中的作用知之甚少。为了阐明影响 NOB 群落组成的关键因素，设计了实验室规模的序批式反应器（SBR），并在与实际废水处理厂相同的条件下运行，以实现相当的氮去除和相似的群落；然后，应用了不同的条件，包括温度（T）、溶解氧（DO）、游离亚硝酸（FNA）和游离氨（FA）。基于 16S rRNA 基因的 PCR 和序列分析表明，Nitrotoga 即使在环境温度下也很丰富，因此进一步挑战了它们仅适应寒冷的先前概念。在缺氧条件下，Nitrotoga 比 更不具有竞争力，表明其对溶解氧的亲和力较低。由于相对较高的抗性，Nitrotoga 是在常规暴露于 FNA 和 FA 下的主要亚硝酸盐氧化菌，这两种有效杀菌剂。因此，本研究表明，Nitrotoga 可以在生物脱氮中发挥重要作用，也凸显了需要采取多种策略来抑制下一代短程脱氮的 NOB。
