Biotransformation of lincomycin and fluoroquinolone antibiotics by the ammonia oxidizers AOA, AOB and comammox: A comparison of removal, pathways, and mechanisms

Abstract

In this study, we evaluated the biotransformation mechanisms of lincomycin (LIN) and three fluoroquinolone antibiotics (FQs), ciprofloxacin (CFX), norfloxacin (NFX), and ofloxacin (OFX), which regularly enter aquatic environments through human activities, by different ammonia-oxidizing microorganisms (AOM). The organisms included a pure culture of the complete ammonia oxidizer (comammox) Nitrospira inopinata , an ammonia oxidizing archaeon (AOA) Nitrososphaera gargensis , and an ammonia-oxidizing bacterium (AOB) Nitrosomonas nitrosa Nm90. The removal of these antibiotics by the pure microbial cultures and the protein-normalized biotransformation rate constants indicated that LIN was significantly co-metabolically biotransformed by AOA and comammox, but not by AOB. CFX and NFX were significantly co-metabolized by AOA and AOB, but not by comammox. None of the tested cultures transformed OFX effectively. Generally, AOA showed the best biotransformation capability for LIN and FQs, followed by comammox and AOB. The transformation products and their related biotransformation mechanisms were also elucidated. i) The AOA performed hydroxylation, S-oxidation, and demethylation of LIN, as well as nitrosation and cleavage of the piperazine moiety of CFX and NFX; ii) the AOB utilized nitrosation to biotransform CFX and NFX; and iii) the comammox carried out hydroxylation, demethylation, and demethylthioation of LIN. Hydroxylamine, an intermediate of ammonia oxidation, chemically reacted with LIN and the selected FQs, with removals exceeding 90%. Collectively, these findings provide important fundamental insights into the roles of different ammonia oxidizers and their intermediates on LIN and FQ biotransformation in nitrifying environments including wastewater treatment systems.

Free Nitrous Acid Inhibits Atenolol Removal during the Sidestream Partial Nitritation Process through Regulating Microbial-Induced Metabolic Types

“…Compared with conventional activated sludge, pharmaceutical removal efficiencies can be enhanced by nitrifying systems. This has been demonstrated in lab-scale enriched nitrifying sludge systems, full-scale nitrification processes, and pure nitrifying microorganism reactors. , The positive correlation between pharmaceutical removal efficiency and nitrifying activities proved the significance of cometabolism in biodegradation of pharmaceuticals. ,, Ammonia-oxidizing bacteria (AOB) were capable of cometabolically catalyzing the biodegradation of various organic substrates in the obligatory presence of ammonium, owing to the nonspecific enzyme ammonia monooxygenase (AMO) . Recently, ammonia-oxidizing archaea and a complete ammonia oxidizer (comammox) also showed their abilities in cometabolic biodegradation of pharmaceuticals. , In addition to AOB-induced cometabolism, metabolic biodegradation by microorganisms (e.g., heterotrophs) could also contribute to removal of nontoxic pharmaceuticals, which were utilized as energy and carbon sources …”

“…This has been demonstrated in lab-scale enriched nitrifying sludge systems, 10 full-scale nitrification processes, 11 and pure nitrifying microorganism reactors. 5,12 The positive correlation between pharmaceutical removal efficiency and nitrifying activities proved the significance of cometabolism in biodegradation of pharmaceuticals. 10,13,14 bacteria (AOB) were capable of cometabolically catalyzing the biodegradation of various organic substrates in the obligatory presence of ammonium, owing to the nonspecific enzyme ammonia monooxygenase (AMO).…”

“…15 Recently, ammoniaoxidizing archaea and a complete ammonia oxidizer (comammox) also showed their abilities in cometabolic biodegradation of pharmaceuticals. 5,12 In addition to AOBinduced cometabolism, metabolic biodegradation by microorganisms (e.g., heterotrophs) could also contribute to removal of nontoxic pharmaceuticals, which were utilized as energy and carbon sources. 16 An energy-and carbon-efficient autotrophic partial nitritation/anammox (PN/A) process has been developed and widely applied for nitrogen removal.…”

AuAg Nanoparticles Grafted on TiO2@N-Doped Porous Carbon: Improved Depletion of Ciprofloxacin under Visible Light through Plasmonic Photocatalysis

“…Indeed, they pose a risk to the environment, ecology and the health of human beings [ 1 ], especially considering that wastewater treatment plants (WWTPs) were not a priori conceived to handle this kind of pollutants [ 2 ]. In this regard, ciprofloxacin (CIP), a widely used antibiotic, displays inert chemical bonds, which makes CIP very difficult to degrade by microorganisms and remains persistent in wastewater [ 3 ].…”

Enhanced biodegradation of ciprofloxacin by enriched nitrifying sludge: assessment of removal pathways and microbial responses

“…Ciprofloxacin is the most widely used fluoroquinolone antibiotics due to its activity against a wide range of Gram-negative and Gram-positive bacteria (Davis et al 1996;Picó & Andreu 2007). Zhou et al (2021) found that pure cultures of AOB or ammonia oxidizing archaea (AOA) instead of the complete ammonia oxidizer (comammox) could significantly biotransformed ciprofloxacin and norfloxacin via cometabolism. Although nitrifying bacteria were already known to exhibit remarkable performance in the removal of ciprofloxacin (Dorival-García et al 2013;Wang et al 2017), little information was yet available on the interactions between the AOB activity and fluoroquinolone (e.g., ciprofloxacin) along with its degradation products so far.…”