N. CHITRA, B.K. NAYAK AND ANIMA NANDA
Abstract
The environmental friendly approach is employed to synthesise silver nanoparticles from the endophytic fungi, which is reservoir of novel bioactive secondary metabolites showing antibacterial, anti-insect, anticancer, anti-diabetic and immune suppressant activity. In the present study, the Alternaria alternate (MTCC-2604) has been exploited for the green synthesis in which the biomolecules induce the reduction of Ag+ ions from silver nitrate to silver nanoparticle. The appearance of dark brown color from yellowish colour in the conical flask suggested the formation of AgNPs. The UV-Visible spectrum of the aqueous medium containing silver ions demonstrated a peak at 430nm corresponding to the plasmon absorbance of silver nanoparticles. The FESEM study of silver nanoparticles showed AgNPs were spherical in shape and individual nanoparticles as well as few aggregate having size in the range 50-100 nm.The biologically synthesised silver nanoparticles showed good bactericidal action against tested human pathogens. While studying the combined effect of silver nanoparticles with antibiotics Tetracycline (30mcg) and Penicillin-G (10mcg); enhanced the bactericidal activity. Thus we conclude that the silver nanoparticles along with antibiotics could become the novel remedy substituent in the place of higher doses of antibiotics.