Minicells as an Escherichia coli mechanism for the accumulation and disposal of fluorescent cadmium sulphide nanoparticles
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Archivos
Fecha
2024-02-27
Profesor/a Guía
Facultad/escuela
Idioma
en
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Título del volumen
Editor
Scientific Research Publishing
Nombre de Curso
Licencia CC
ATTRIBUTION 4.0 INTERNATIONAL
https://creativecommons.org/licenses/by/4.0/
https://creativecommons.org/licenses/by/4.0/
Licencia CC
Resumen
Background Bacterial biosynthesis of fluorescent nanoparticles or quantum dots (QDs) has emerged as a unique mechanism for heavy metal tolerance. However, the physiological pathways governing the removal of QDs from bacterial cells remains elusive. This study investigates the role of minicells, previously identified as a means of eliminating damaged proteins and enhancing bacterial resistance to stress. Building on our prior work, which unveiled the formation of minicells during cadmium QDs biosynthesis in Escherichia coli, we hypothesize that minicells serve as a mechanism for the accumulation and detoxification of QDs in bacterial cells. Results Intracellular biosynthesis of CdS QDs was performed in E. coli mutants Delta minC and Delta minCDE, known for their minicell-producing capabilities. Fluorescence microscopy analysis demonstrated that the generated minicells exhibited fluorescence emission, indicative of QD loading. Transmission electron microscopy (TEM) confirmed the presence of nanoparticles in minicells, while energy dispersive spectroscopy (EDS) revealed the coexistence of cadmium and sulfur. Cadmium quantification through flame atomic absorption spectrometry (FAAS) demonstrated that minicells accumulated a higher cadmium content compared to rod cells. Moreover, fluorescence intensity analysis suggested that minicells accumulated a greater quantity of fluorescent nanoparticles, underscoring their efficacy in QD removal. Biosynthesis dynamics in minicell-producing strains indicated that biosynthesized QDs maintained high fluorescence intensity even during prolonged biosynthesis times, suggesting continuous QD clearance in minicells. Conclusions These findings support a model wherein E. coli utilizes minicells for the accumulation and removal of nanoparticles, highlighting their physiological role in eliminating harmful elements and maintaining cellular fitness. Additionally, this biosynthesis system presents an opportunity for generating minicell-coated nanoparticles with enhanced biocompatibility for diverse applications.
Notas
Palabras clave
Minicells, Quantum dots, Nanoparticles, Cell division, Cadmium, Escherichia coli, Tolerance mechanisms
Citación
JOURNAL OF NANOBIOTECHNOLOGY, Volume 22, Issue 1, 2024.
DOI
10.1186/s12951-024-02348-0