Rapid removal of chloramphenicol via the synergy of Geobacter and metal oxide nanoparticles

Green synthesis, characterization and drug-loaded iron oxide nanoparticles derived from Nerium oleander flower extract as a nanocarrier for in vitro antibacterial efficacy

“…When iron and streptomycin are mixed, phospholipids are formed [61]. The sulfate group forms a covalent bond, enveloping the nanoparticles in a coating [62]. Following that, the conjugate mostly leads to cell annihilation via two mechanisms: at first by limiting protein synthesis, and secondly, by damaging cell membranes.…”

Electron shuttles enhanced the removal of antibiotics and antibiotic resistance genes in anaerobic systems: A review

“… Liu et al (2022) found that the input of biogenic carbon into the anaerobic system was effective in mitigating the horizontal gene transfer effect of Cu(II) on ARGs between Escherichia coli DH5α and E. coli HB101 through the regulation of three globally regulated genes ( korA, korB, trbA ). Xiao et al’s (2022) study pointed out that the removal of chloramphenicol by microbial fuel cell containing the electroactive bacteria Geobacter metallireducens could increase from about 50 to 100% after addition of Fe 3 O 4 and MnO 2 nanoparticles, respectively. Mechanistic analysis showed that Fe 3 O 4 nanoparticles mainly enhanced the expression of C-type cytochromes and ethanol dehydrogenase, while MnO 2 nanoparticles mainly enhanced the expression of type IV pili and pyruvate dehydrogenase, the expression of NADH-quinone oxidoreductase was increased by both nanoparticles ( Xiao et al, 2022 ).…”

“…Mainly, (1) carbon-based and metal-based materials cast into anaerobic systems, especially in wastewater treatment, serve as good carriers for microbial growth and can significantly improve microbial growth activity ( Zhao Z. S. et al, 2020 ; Yang et al, 2021a ); (2) antibiotics in the aqueous phase are adsorbed onto the surface of the electron shuttle by adsorption ( Zhao Z. S. et al, 2020 ; Cheng et al, 2021 ), due to their excellent electrical conductivity acting as an microbial-antibiotic “electron bridge” to enhance the electron transfer process ( Zhang Z. H. et al, 2018 ; Zhou et al, 2021c ); (3) the pili and cytochrome C of bacteria are important mediators of the microbial extracellular electron transfer process. It has been pointed out that metal oxides (e.g., Fe 3 O 4 , MnO 2 ) help to stimulate the expression of relevant functional genes and promote them with different effects ( Xiao et al, 2022 ). In some cases Fe 3 O 4 can replace cytochrome C to play an extracellular electron transfer role ( Jin et al, 2019 ); (4) for some metal-based electron shuttles, efficient electron transfer can be achieved with the help of cycling of high and low valence of dissolved metal ions, such as Mn(IV)/Mn(II) cycle and Fe(III)/Fe(II) cycle ( Xu et al, 2022 ).…”