Biosynthesis and Comparison silver nanoparticles production by Fusarium oxysporum in the presence of silver nitrate and sulfate

In recent years, various chemical and physical methods have been employed for the synthesis of metal nanoparticles, these methods have certain disadvantages due to involvement of toxic chemicals and radiation. It is well known that many microorganisms like algae, bacteria and fungi produce nanoparticles either intra and extracellularly. Fusarium oxysporum is a facultative anaerobic fungus and can thrive under oxygen limitation so In this research we investigated extracellular biosynthesis of silver nanoparticles by Fusarium oxysporum in anaerobic condition when challenged with silver nitrate and silver sulfate as source of terminal acceptor electron. The formation of nanoparticles was characterized by visual observation followed by UV–Vis spectrophotometric analysis, which showed a peak at 400-460 nm in both methods, which is specific for silver nanoparticles. The results revealed that F. oxysporum synthesizes higher amount of silver nanoparticle when challenged with silver nitrate solution. We suggest there are pathways for silver ion reduction by F. oxysporum other than nitrate reductase but nitrate reductase pathway plays an important role here.

Keywords:

Fusarium oxysporum , silver nanoparticle , anaerobic , silver sulfate , silver nitrate