Efficient remediation of meropenem using Bacillus tropicus EMB20 β-lactamase immobilized on magnetic nanoparticles. (1st March 2023)

• Record Type: Journal Article
• Authors: Fatima, Huma; Bhattacharya, Amrik; Khare, Sunil Kumar
• Is Part Of: Journal of environmental management. Volume 329(2023)
• Publication Date: 2023-03-01
• Subjects: Bioremediation -- β-lactamase -- Immobilization -- Meropenem -- Nanoconjugate; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2022.117054
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Reducing antibiotic pollution in the environment in essential to preserve the effectiveness of the available antibiotics. In the present study, β-lactamase from Bacillus tropicus EMB20 was immobilized onto magnetic nanoparticles (Fe3 O4 ) through covalent coupling method. The nanoconjugate was structurally characterized using SEM, FTIR, UV-spectrometry, and XRD diffraction analyses. The prepared enzyme nanoconjugate was thereafter used for remediation of meropenem (Mer) and showed complete removal of 10 mgL −1 Mer within 3 h of treatment. Moreover, the immobilized enzyme was successfully recovered and reused for up to 5 cycles with 57% removal efficiency. The immobilized preparation was also observed to be effective in the removal of higher Mer concentrations of 25 and 50 mgL −1 with 79% and 75% removal efficiency, respectively. The major hydrolyzed product of Mer was found to be opened-lactam ring structure with m/z 402.16. The hydrolyzed product(s) were observed to be non-toxic as revealed through microbial MTT, confocal microscopy, and growth studies. Under the mixed conditions of 50 mgL −1 ampicillin (Amp), 10 mgL −1 amoxicillin (Amox) and, Mer, the nanoconjugate showed simultaneous complete removal of Amp and Mer, while 49% Amox removal was detected after 3 h of treatment. Moreover, the nanoconjugates also showed concomitant complete removal of antibiotic mixture with in 2 h from aquaculture wastewater. Overall, the study comes out with an efficient approach for remediation of β-lactam antibiotics from contaminated systems. Graphical abstract: Image 1 Highlights: Bacillus tropicus EMB20 β-lactamase was immobilized on magnetic nanoparticles. Immobilization efficiency of the nanoconjugate was determined to be 50.3%. Nanoconjugate catalysed 89% of 10 mgL −1 Mer in 1 h of treatment. The enzymatic hydrolysis pathway of meropenem was proposed. The Mer hydrolyzed products were characterized for antibacterial activity and toxicity.