Responses of microbial interactions and functional genes to sulfamethoxazole in anammox consortia

• Published in: Journal of environmental management 2023-12, Vol.348, p.119408-119408, Article 119408
• Main Authors: Hu, Meina, Liu, Xiaojing, Liu, Shidi, Ya, Tao, Zhang, Minglu, Zhang, Tingting, Gao, Xiaoping, Wang, Xiaohui
• Format: Article
• Language: English
• Subjects: Anammox consortia; Functional gene; Microbial interactions; Sulfamethoxazole
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2023.119408

Sulfamethoxazole (SMX) has been widely detected in various environments and its potential environmental risks have caused great concerns. However, the impact mechanism of SMX on microbial interactions among anammox consortia remain unknown. A long-term exposure experiments (140 d) was carried out to systematically examine the influence of SMX (0–1000 μg/L) on the anammox system, especially microbial network dynamics and variations of key metabolic genes. Results showed that anammox system could adapt to SMX below 500 μg/L and maintain a high nitrogen removal efficiency (NRE) of 85.35 ± 2.42%, while 1000 μg/L SMX significantly decreased the abundance of functional microbes and deteriorated denitrification performance with NRE dropped to 36.92 ± 15.01%. Co-occurrence network analysis indicated that 1000 μg/L SMX decreased the interactions between Proteobacteria and Chloroflexi and limited AnAOB from playing an important role as central nodes in the subnetwork of Planctomycetes. Metagenomics analysis found that genes associated with nitrogen removal (i.e., hdh, hzs, nirS, and hao) showed lower expression level after addition of SMX, while SMX-related ARGs (sul1 and sul2) increased by 1.22 and 2.68 times. This study provided us a relatively comprehensive perspective in response of microbial interactions and metabolic activity to various SMX concentrations. [Display omitted] •Anammox could adapt to100 and 500 μg/L SMX but was severely inhibited by 1000 μg/L SMX.•SMX increased the deterministic process in the microbial community assembly.•100 and 1000 μg/L SMX simplified while 500 μg/L SMX complicated the overall network.•1000 μg/L SMX limited AnAOB from acting as central nodes in the subnetwork of Planctomycetes.•SMX decreased the abundance of nitrogen metabolism genes but increased SMX-realated ARGs.