Resistance genes and extracellular proteins relieve antibiotic stress on the anammox process

Extracellular polymeric substances—antibiotics interaction in activated sludge: A review

“…Similarly, Xu et al. [ 39 ] observed that the static quenching of fluorophores in EPS proteins with 25 mg L −1 sulfamethazine adsorption and the Gibbs free energy of the sulfamethazine binding onto sludge EPS was thermodynamically favorable, which revealed a spontaneous binding process and stable EPS-antibiotics complex formation [ 9 ]. reported that the zeta potential of the EPS-sulfamethoxazole complex increased with increasing concentrations.…”

“…Therefore, EPS-related proteins play an essential role in antibiotics binding via complex interactions, including hydrophobic effects, cation bridging, and polymer entanglement, to form a dense network structure to guard against adverse stress [ 53 ]. The increased protein/polysaccharide ratio also indicated that the hydrophobicity of sludge samples increased [ 9 , 44 ].…”

“…Antibiotics entering the wastewater biological treatment system adhere to the sludge floc and cause different variations in some physical parameters (e.g., zeta potential and contact angle) and chemical composition (e.g., α-helix/(β-sheet + random coil) and β-sheet value) of EPS [ [43] , [133] ]. For example, the zeta potential of EPS was obviously increased with exposure to antibiotics (e.g., sulfamethoxazole and erythromycin) [ 9 ], whereas it gradually declined after binding with heavy metals (e.g., As(III), Cd (II), Pb (II), and Cr (VI)) [ [43] , [134] ]. In addition to zeta potential, the secondary protein structure of EPS showed a different trend under the stress of As(III) and sulfamethoxazole (SMX).…”

“…Recently, several studies have confirmed and emphasized the role of EPS in antibiotic stress resistance during WWTPs operation [ 2 , 9 , 10 ]; however, systematic and in-depth analyses of EPS feedback under different antibiotics exposures, especially the complex interactions and potential mechanisms between the antibiotics and EPS are still lacking, which limits the potential application of sludge EPS for antibiotics removal. Therefore, the interactions between EPS and antibiotics were systematically elucidated and analyzed.…”

The influence of antibiotics on the anammox process — a review

“…Moreover, it has been proven that many bacteria involved in nitrogen removal from wastewater or occurring in denitrifying systems, such as Nitrospira , Ignavibacterium , and Comamonas play an important role as ARG-carrying bacteria. The role of anammox bacteria as hotspot of antibiotics resistance genes was investigated by Fan et al ( 2021 ). The authors presented positive correlation between Candidatus Kuenenia and sul1 (gene encoding resistance for sulfonamides).…”