Related Experiment Video
Updated: Jan 30, 2026

Ameliorating Osteoarthritis in Mice Using Silver Nanoparticles
Published on: June 2, 2023
Biosynthesis of silver nanoparticles by cell-free extracts from some bacteria species for dye removal from wastewater
Nanis G Allam1, Gehan A Ismail1, Walaa M El-Gemizy1
1Microbiology Division, Botany Department, Faculty of Science, Tanta University, Tanta, 31527, Egypt.
Objectives:
To investigate the biosynthesis of silver nanoparticles (AgNPs) using extracts of some bacterial isolates Bacillus pumilus, Bacillus paralicheniformis and Sphingomonas paucimobilis. The formation of AgNPs was detected by the change in color into yellow and confirmed by the UV-Vis spectroscopy. The nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR).
Results:
The obtained AgNPs were spherical to oval in shape with particle size ranged from 4 to 20 nm and surface area 118 m2/g. The AgNPs have been used as nanocatalyst for the removal of malachite green dye (MG) from aqueous solution. The dye was chosen as a model dye released in wastewater. The AgNPs showed excellent nanocatalyst for the removal of MG. The dye removal process was observed by the continuous decrease in dye absorbance at 617 nm until it vanished over 160 min. The removal kinetics followed closely the pseudo-first-order kinetic model.
Conclusion:
The B. paralicheniformis strain KJ-16 was the most effective isolated bacteria to give extract for biosynthesis of AgNPs and dye removal. This method may be considered easy and eco-friendly, and could be applicable for large-scale decontamination of wastewater from harmful dyes.
Related Concept Videos
Biosynthesis in Bacteria
What is a Species?
Biosynthesis of Polysaccharides
Biosynthesis of Lipids
Keystone Species
Formation of Species

