Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology , University of Vienna , Althanstrasse 14 , 1090 Vienna , Austria.
Department of Civil and Environmental Engineering , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States.
Environ Sci Technol. 2019 Aug 6;53(15):8695-8705. doi: 10.1021/acs.est.9b01037. Epub 2019 Jul 19.
The recently discovered complete ammonia-oxidizing (comammox) bacteria occur in various environments, including wastewater treatment plants. To better understand their role in micropollutant biotransformation in comparison with ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), we investigated the biotransformation capability of (the only comammox isolate) for 17 micropollutants. Asulam, fenhexamid, mianserin, and ranitidine were biotransformed by , (AOA), and Nm90 (AOB). More distinctively, carbendazim, a benzimidazole fungicide, was exclusively biotransformed by . The biotransformation of carbendazim only occurred when was supplied with ammonia but not nitrite as the energy source. The exclusive biotransformation of carbendazim by was likely enabled by an enhanced substrate promiscuity of its unique AMO and its much higher substrate (for ammonia) affinity compared with the other two ammonia oxidizers. One major plausible transformation product (TP) of carbendazim is a hydroxylated form at the aromatic ring, which is consistent with the function of AMO. These findings provide fundamental knowledge on the micropollutant degradation potential of a comammox bacterium to better understand the fate of micropollutants in nitrifying environments.
最近发现的完整氨氧化（comammox）细菌存在于各种环境中，包括废水处理厂。为了更好地了解它们在与氨氧化细菌（AOB）和氨氧化古菌（AOA）相比在微污染物生物转化中的作用，我们研究了（唯一的 comammox 分离株）对 17 种微污染物的生物转化能力。除草定、苯霜灵、米氮平、雷尼替丁可被 、AOA 和 Nm90（AOB）生物转化。更显著的是，苯并咪唑类杀菌剂多菌灵可被 独家生物转化。只有当 以氨而不是亚硝酸盐作为能源时，多菌灵的生物转化才会发生。由于其独特的 AMO 增强了底物的混杂性及其与其他两种氨氧化菌相比更高的底物（氨）亲和力，使得 能够独家生物转化多菌灵。多菌灵的一个主要可能的转化产物（TP）是芳环上的羟基化形式，这与 AMO 的功能一致。这些发现提供了 comammox 细菌对微污染物降解潜力的基本认识，以更好地了解硝化环境中微污染物的命运。
