New approach for antimicrobial activity and bio-control of various pathogens by biosynthesized copper nanoparticles using endophytic actinomycetes

Abstract

The biosynthesis of nanoparticles by microorganisms especially endophytic species isolated from medicinal plant are the prime concern of researchers. In the present study, a novel, non-toxic, eco-friendly copper nanoparticles was biosynthesized by endophytic actinomycetes isolate Ca-1 and optimization processes have been endeavored. The endophytic actinomycete Streptomyces capillispiralis Ca-1, was isolated from healthy medicinal plant (Convolvulus arvensis) (L.) collected from Bahariya Oasis - Giza Governorate – Egypt. The isolate was identified by morphological, cultural and molecular identification techniques. The biosynthesis of CuNPs is confirmed by gradual change of biomass filtrate color from light blue into greenish brown color and characterized by an observation of a characteristic absorption peak by UV-Vis spectroscopy at 600 nm. Also, a spherical-monodispersed shaped CuNPs with particle size of 3.6–59 nm were observed by Transmission Electron Microscopy (TEM). In addition, X-ray diffraction (XRD) exhibited pattern peaks corresponding to 110, 111, 200, 220, 311 and 222 planes, respectively that assigned to face centered cubic forms of metallic copper (JCPDS 04–0836). While FTIR results confirmed the occurrence of bioactive functional groups that are responsible for formation of CuNPs. Moreover, the biosynthesized CuNPs showed various biomedical applications against infectious microorganisms, biocontrol of phytopathogenic fungi and health nasty insects that represent the hopeful uses of copper nanoparticles to be applied as a unique approach to manage these healths threatening problems. Keywords: Copper nanoparticles, Endophytic actinomycetes, Streptomyces capillispiralis, Biomedical applications