Department of Microbiology and Biotechnology, Universität Hamburg, Hamburg, Germany.
Appl Microbiol Biotechnol. 2021 Oct;105(19):7123-7139. doi: 10.1007/s00253-021-11487-5. Epub 2021 Sep 11.
Many biotechnological applications deal with nitrification, one of the main steps of the global nitrogen cycle. The biological oxidation of ammonia to nitrite and further to nitrate is critical to avoid environmental damage and its functioning has to be retained even under adverse conditions. Bacteria performing the second reaction, oxidation of nitrite to nitrate, are fastidious microorganisms that are highly sensitive against disturbances. One important finding with relevance for nitrogen removal systems was the discovery of the mainly cold-adapted Cand. Nitrotoga, whose activity seems to be essential for the recovery of nitrite oxidation in wastewater treatment plants at low temperatures, e.g., during cold seasons. Several new strains of this genus have been recently described and ecophysiologically characterized including genome analyses. With increasing diversity, also mesophilic Cand. Nitrotoga representatives have been detected in activated sludge. This review summarizes the natural distribution and driving forces defining niche separation in artificial nitrification systems. Further critical aspects for the competition with Nitrospira and Nitrobacter are discussed. Knowledge about the physiological capacities and limits of Cand. Nitrotoga can help to define physico-chemical parameters for example in reactor systems that need to be run at low temperatures. KEY POINTS: • Characterization of the psychrotolerant nitrite oxidizer Cand. Nitrotoga • Comparison of the physiological features of Cand. Nitrotoga with those of other NOB • Identification of beneficial environmental/operational parameters for proliferation.
许多生物技术应用都涉及硝化作用，这是全球氮循环的主要步骤之一。氨的生物氧化为亚硝酸盐，再进一步氧化为硝酸盐，对于避免环境破坏至关重要，即使在不利条件下，其功能也必须保留。进行第二步反应，将亚硝酸盐氧化为硝酸盐的细菌是挑剔的微生物，对干扰非常敏感。对于氮去除系统，一个重要的发现是主要适应寒冷的 Cand. Nitrotoga 的发现，其活性似乎对于在低温下（例如在寒冷季节）从废水中恢复亚硝酸盐氧化至关重要。最近已经描述并在生态生理学上对该属的几个新菌株进行了研究，包括基因组分析。随着多样性的增加，在活性污泥中也检测到了嗜温的 Cand. Nitrotoga 代表。这篇综述总结了自然分布和定义人工硝化系统中生态位分离的驱动力。还讨论了与 Nitrospira 和 Nitrobacter 竞争的关键方面。了解 Cand. Nitrotoga 的生理能力和限制有助于为需要在低温下运行的反应器系统定义物理化学参数。关键点：• 耐冷亚硝酸盐氧化菌 Cand. Nitrotoga 的特性• 与其他 NOB 相比 Cand. Nitrotoga 的生理特征• 确定增殖的有益环境/操作参数。
