Mutual influence mechanism of nitrate and sulfamethoxazole on their biotransformation in poly (3-hydroxybutyrate-3-hydroxyvalerate) supported denitrification biofilter for a long-term operation

Zhongshuo Xu; Siwen Ze; Xueting Chen; Xinshan Song; Yuhui Wang

doi:10.1016/j.jenvman.2023.118897

Mutual influence mechanism of nitrate and sulfamethoxazole on their biotransformation in poly (3-hydroxybutyrate-3-hydroxyvalerate) supported denitrification biofilter for a long-term operation

J Environ Manage. 2023 Nov 1:345:118897. doi: 10.1016/j.jenvman.2023.118897. Epub 2023 Sep 6.

Authors

Zhongshuo Xu¹, Siwen Ze², Xueting Chen³, Xinshan Song², Yuhui Wang⁴

Affiliations

¹ Donghua University, College of Environmental Science and Engineering, Shanghai, 201600, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China. Electronic address: xuzhongshuo@dhu.edu.cn.
² Donghua University, College of Environmental Science and Engineering, Shanghai, 201600, China.
³ Shanghai Fisheries Research Institute, Shanghai Fisheries Technical Extension Station, Shanghai, 200433, China.
⁴ Donghua University, College of Environmental Science and Engineering, Shanghai, 201600, China. Electronic address: yhwang@dhu.edu.cn.

PMID: 37683386
DOI: 10.1016/j.jenvman.2023.118897

Abstract

Nitrate and SMX both play a critical role in their biotransformation in biodegradable polymer-supported denitrification biofilters. However, the mutual influences of nitrate and SMX on their biotransformation for long-term operation remained obscure. Results showed SMX and nitrate had divergent effects on SMX removal. SMX removal rates was positively related with its loading rates, whereas they were negatively related to NLRs. The most abundant metabolite C₁₀H₁₄O₃N₃S (the reduced form of SMX moiety) from the N-O bond cleavage pathway by UHPLC-LTQ-Orbitrap-MS/MS and effluent TOC variations confirmed the presence of electron donor competition between nitrate and SMX. SMX less than 1000 μg/L had a negligible influence on denitrification performance. Denitrifiers such as Azospira and Denitratisoma were still enriched after chronic exposure, and nosZ/narG positively correlated with sul1/sul2 resistance genes, which were both responsible for the negligible influence of SMX. This work could guide the operational management of denitrification biofilters for simultaneous nitrate and antibiotics removal.

Keywords: Denitrification; Denitrification gene; Microbial community structure; Resistant gene; SMX biotransformation.

MeSH terms

3-Hydroxybutyric Acid
Biotransformation
Denitrification
Hydroxybutyrates
Nitrates*
Sulfamethoxazole*
Tandem Mass Spectrometry

Substances

Nitrates
beta-hydroxyvaleric acid
3-Hydroxybutyric Acid
Sulfamethoxazole
Hydroxybutyrates