Novel Alcaligenes ammonioxydans sp. nov. from wastewater treatment sludge oxidizes ammonia to N2 with a previously unknown pathway

Autor(en)

Meng-Ru Wu, Ting-Ting Hou, Ying Liu, Li-Li Miao, Guo-Min Ai, Lan Ma, Hai-Zhen Zhu, Ya-Xin Zhu, Xi-Yan Gao, Craig W Herbold, Michael Wagner, De-Feng Li, Zhi-Pei Liu, Shuang-Jiang Liu

Abstrakt

Heterotrophic nitrifiers are able to oxidize and remove ammonia from nitrogen-rich wastewaters but the genetic elements of heterotrophic ammonia oxidation are poorly understood. Here, we isolated and identified a novel heterotrophic nitrifier, Alcaligenes ammonioxydans sp. nov. strain HO-1, oxidizing ammonia to hydroxylamine and ending in the production of N2 gas. Genome analysis revealed that strain HO-1 encoded a complete denitrification pathway but lacks any genes coding for homologous to known ammonia monooxygenases or hydroxylamine oxidoreductases. Our results demonstrated strain HO-1 denitrified nitrite (not nitrate) to N2 and N2 O at anaerobic and aerobic conditions respectively. Further experiments demonstrated that inhibition of aerobic denitrification did not stop ammonia oxidation and N2 production. A gene cluster (dnfT1RT2ABCD) was cloned from strain HO-1 and enabled E. coli accumulated hydroxylamine. Sub-cloning showed that genetic cluster dnfAB or dnfABC already enabled E. coli cells to produce hydroxylamine and further to 15 N2 from (15 NH4 )2 SO4 . Transcriptome analysis revealed these three genes dnfA, dnfB and dnfC were significantly upregulated in response to ammonia stimulation. Taken together, we concluded that strain HO-1 has a novel dnf genetic cluster for ammonia oxidation and this dnf genetic cluster encoded a previously unknown pathway of direct ammonia oxidation (Dirammox) to N2 .

Organisation(en)

Department für Mikrobiologie und Ökosystemforschung

Externe Organisation(en)

University of the Chinese Academy of Sciences, Aalborg University (AAU), Shandong University

Journal

Environmental Microbiology

Band

23

Seiten

6965-6980

Anzahl der Seiten

16

ISSN

1462-2912

DOI

https://doi.org/10.1111/1462-2920.15751

Publikationsdatum

11-2021

Peer-reviewed

Ja

ÖFOS 2012

106014 Genomik, 106022 Mikrobiologie

Schlagwörter

ASJC Scopus Sachgebiete

Ecology, Evolution, Behavior and Systematics, Microbiology

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/c7046561-0486-4713-891e-428e5660abcb