Characterization of a novel Pseudomonas mosselii 9-1 capable of nitrate reduction to ammonium, ammonium assimilation, and denitrification in aerobic conditions

• Published in: Journal of water process engineering 2023-04, Vol.52, p.103531, Article 103531
• Main Authors: Cai, Xiaoni, Liu, Ruijie, Cheng, Mengjie, Liu, Tianjia, Zhang, Yue, Li, Xinke, Zeng, Yanhua, Long, Hao, Ren, Wei, Xie, Zhen-yu
• Format: Article
• Language: English
• Subjects: Ammonium assimilation; Dissimilatory nitrate reduction to ammonium; Nitrogen metabolic pathways; Pseudomonas mosselii 9-1
• ISSN: 2214-7144; 2214-7144
• DOI: 10.1016/j.jwpe.2023.103531

Pseudomonas mosselii 9-1 was isolated from Litopenaeus vannamei aquaculture wastewater and effectively removed ammonium and nitrate, with 98 % of ammonium and 45 % of nitrate removed within 24 h. Moreover, P. mosselii 9-1 tolerated as high as 2500 mg/L of ammonium along with the elimination of approximately 588 mg/L of it within 24 h. KEGG analysis revealed that rather than nitrification, P. mosselii 9-1 removes ammonium via heterotrophic ammonium assimilation, the presence of nirBD and nirK genes implicated reduction to ammonium and aerobic denitrification reduction to gaseous nitrogen, as the pathways involved in NO2− removal. Additionally, P. mosselii 9-1 can transform organic nitrogen to NH3 through ammonification. Single-factor analyses revealed a C/N ratio of 18, a temperature of >20 °C, pH 6–9, and sodium succinate as a source of carbon, favored the removal of ammonium and nitrate. P. mosselii 9-1 may be a promising biotreatment agent for wastewater containing high ammonium levels. [Display omitted] •P. mosselii 9-1 can effectively remove ammonium and nitrate from waster water.•P. mosselii 9-1 is capable of nitrate reduction to ammonium, ammonium assimilation, denitrification and ammonification.•Factors that influence the removal efficiency of ammonium and nitrate were investigated.