Actinomycetes-mediated biogenic synthesis of metal and metal oxide nanoparticles: progress and challenges

Abstract

Actinomycetes-mediated biogenic synthesis of metal nanoparticles and their antimicrobial activities are well documented. Actinomycetes facilitate both intracellular and extracellular metal nanoparticles synthesis and are efficient candidates for the production of polydispersed, stable and ultra-small size metal nanoparticles. Secondary metabolites and new chemical entities derived from Actinomycetes have not been extensively studied for the synthesis of metal/metal oxide nanoparticles. The present review focuses on biogenic synthesis of metal nanoparticles from Actinomycetes and the scope for exploring Actinomycetesderived compounds (enzymes, organics acids and bioactive compounds) as metal and metal oxide reducing agents for the synthesis of desired nanoparticles. This review also focuses on challenges faced in the applications of nanoparticles and the methods to synthesize biogenic metal nanoparticles with desired physiochemical properties such as ultra-small size, large surface to mass ratio, high reactivity etc. Methods to evade their toxicity and unique interactions with biological systems to improve their chance as an alternative therapeutic agent in medical and pharmaceutical industry are also discussed.

Bactericidal and In-Vitro Cytotoxic Efficacy of Silver Nanoparticles (Ag-NPs) Fabricated by Endophytic Actinomycetes and Their Use as Coating for the Textile Fabrics

“…Moreover, Bacillus subtilis presented the highest sensitivity to the silver nano-antibiotics, while the lowest sensitivity was assigned to Salmonella typhimurium . Bio-colloidal silver synthesized from actinomycetes have exhibited an efficient nano-antibiotics and antibacterial activities [ 64 ]. Corresponding with our investigations, the well diffusion method was used to evaluate the antibacterial properties of Streptomyces sp-induced silver nanoparticles, which displayed good antibacterial activity against Gram-negative and Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) [ 65 ].…”

Endophytic Streptomyces laurentii Mediated Green Synthesis of Ag-NPs with Antibacterial and Anticancer Properties for Developing Functional Textile Fabric Properties

“…Bio-silver nanoparticles derived from actinobacteria previously demonstrated considerable potential as antibacterials [ 47 ]. The antibacterial efficacy of Ag-NPs could be attributed to the binding of silver with the bacterial cell wall through electrostatic attraction between the positive charge of Ag-NPs and the negative charge of the cell wall.…”

A review on the biosynthesis of metal and metal salt nanoparticles by microbes

“…Actinomycetes have been generally used for the synthesis of extracellular enzymes and secondary metabolites. 38 They have also been adopted for the biosynthesis of nanoparticles as they have unsurpassed capacity for the production of various bioactive compounds and contain high protein content. Actinomycetes synthesize nanoparticles via both intracellular and extracellular pathway, but extracellular reduction is the most common pathway and has more commercial applications in different elds.…”