Change of abundance and correlation of Nitrospira inopinata-like comammox and populations in nitrogen cycle during different seasons

• Published in: Chemosphere (Oxford) 2020-02, Vol.241, p.125098-125098, Article 125098
• Main Authors: Lu, Sidan, Sun, Yujiao, Lu, Baiyun, Zheng, Danyang, Xu, Shangwei
• Format: Article
• Language: English
• Subjects: Ammonia - metabolism; Bacteria - cytology; Bacteria - metabolism; Betaproteobacteria; Comammox; Environmental relevance; Geologic Sediments - microbiology; Nitrification; Nitrogen - metabolism; Nitrogen Cycle; Nitrogen-cycle bacteria; Nitrospira inopinata; Oxidation-Reduction; Phylogeny; Rivers - microbiology; Seasons
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2019.125098

Complete-nitrifying bacteria (comammox) play important roles in nitrogen-overloading aquatic systems. However, the understanding of the environmental relevance is still limited. Here, we studied the responses of comammox bacteria (Nitrospira inopinata) in a tributary of the Yellow River, with the water and sediment, microbial, seasonal, and chemical variations considered. Illumina sequencing indicated that the predominant phyla in the river sediment were Proterobacteria, Bacteroidetes, Actinobacteria, and Chloroflex. Quantitative PCR revealed that N. inopinata-like comammox were approximately twice as abundant in the water during the wet season and in the sediment during the dry season than that of other conditions. Significant correlations were found between the abundance of N. inopinata-like comammox and pH (r = 0.58), temperature (r = 0.63), and dissolved oxygen (r = - 0.77). The abundance of N. inopinata-like comammox was higher than that of ammonia oxidizing archaea (AOA), and lower than that of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB). Furthermore, a significant correlation was discovered between N. inopinata-like comammox and NOB (r = 0.60), and so was anammox bacteria (r = 0.358). Interestingly, N. inopinata-like comammox also showed positive relationships with denitrifying microbes (r = 0.559). [Display omitted] •The abundance of N. inopinata-like comammox exceeded AOA, but was overnumbered by AOB, NOB, and the denitrifying microbes.•The abundance of N. inopinata-like comammox significantly correlated with pH, temperature, and dissolved oxygen.•N. inopinata–like comammox had positive relationships with NOB and denitrifying microbes.•The occurrences of the N. inopinata-like comammox in the water and sediments were shaped by seasonal variations.