Cometabolic biotransformation and microbial-mediated abiotic transformation of sulfonamides by three ammonia oxidizers

WATER RESEARCH

卷:159

Article

Zhou, Li-Jun^1,2  Han, Ping^2,3,4  Yu, Yaochun⁵  Wang, Baozhan^2,6  Men, Yujie^5,7  Wagner, Michael^2,8,9  Wu, Qinglong L.^1,10 

[1] Chinese Acad Sci, Nanjing Inst Geog & Limnol, State Key Lab Lake Sci & Environm, Nanjing 210008, Jiangsu, Peoples R China

[2] Univ Vienna, Div Microbial Ecol, Ctr Microbiol & Environm Syst Sci, Althanstr 14, A-1090 Vienna, Austria

[3] East China Normal Univ, State Key Lab Estuarine & Coastal Res, 500 Dongchuan Rd, Shanghai 200241, Peoples R China

[4] East China Normal Univ, Sch Geog Sci, 500 Dongchuan Rd, Shanghai 200241, Peoples R China

[5] Univ Illinois, Dept Civil & Environm Engn, Urbana, IL USA

[6] Chinese Acad Sci, Inst Soil Sci, Nanjing, Jiangsu, Peoples R China

[7] Univ Illinois, Inst Genom Biol, Urbana, IL USA

[8] Univ Vienna, Comammox Res Platform, Vienna, Austria

[9] Aalborg Univ, Dept Biotechnol Chem & Biosci, Aalborg, Denmark

[10] Univ Chinese Acad Sci, Sino Danish Ctr Sci & Educ, Beijing, Peoples R China

关键词: Biotransformation;    Sulfonamides;    Ammonia oxidizers;    Cometabolism;    Abiotic transformation;   

DOI  :  10.1016/j.watres.2019.05.031

来源: Elsevier

【 摘 要 】

The abilities of three phylogenetically distant ammonia oxidizers, Nitrososphaera gargensis, an ammonia oxidizing archaeon (AOA); Nitrosomomas nitrosa Nm90, an ammonia-oxidizing bacterium (AOB); and Nitrospira inopinata, the only complete ammonia oxidizer (comammox) available as a pure culture, to biotransform seven sulfonamides (SAs) were investigated. The removals and protein-normalized biotransformation rate constants indicated that the AOA strain N. gargensis exhibited the highest SA biotransformation rates, followed by N. inopinata and N. nitrosa Nm90. The transformation products (TPs) of sulfadiazine (SDZ), sulfamethazine (SMZ) and sulfamethoxazole (SMX) and the biotransformation mechanisms were evaluated. Based on the analysis of the TP formulas and approximate structures, it was found that during biotransformation, i) the AOA strain carried out SA deamination, hydroxylation, and nitration; ii) the AOB strain mainly performed SA deamination; and iii) the comammox isolate participated only in deamination reactions. It is proposed that deamination was catalyzed by deaminases while hydroxylation and nitration were mediated by nonspecific activities of the ammonia monooxygenase (AMO). Additionally, it was demonstrated that among the three ammonia oxidizers, only AOB contributed to the formation of pterin-SA conjugates. The biotransformation of SDZ, SMZ and SMX occurred only when ammonia oxidation was active, suggesting a cometabolic transformation mechanism. Interestingly, SAs could also be transformed by hydroxylamine, an intermediate of ammonia oxidation, suggesting that in addition to enzymatic conversions, a microbially induced abiotic mechanism contributes to SA transformation during ammonia oxidation. Overall, using experiments with pure cultures, this study provides important insights into the roles played by ammonia oxidizers in SA biotransformation. (C) 2019 Elsevier Ltd. All rights reserved.

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