Fatima H, Bhattacharya A, Khare SK. Efficient remediation of meropenem using Bacillus tropicus EMB20 β-lactamase immobilized on magnetic nanoparticles.
JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023;
329:117054. [PMID:
36549054 DOI:
10.1016/j.jenvman.2022.117054]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
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 (Fe3O4) 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.
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