Biosynthesis of silver nanoparticles (AgNPs) employing Trichoderma strains to control empty-gut disease of oak silkworm (Antheraea pernyi)

Abstract

AgNPs has been used in many areas including agriculture, medicine and industry etc. Biosynthesis of AgNPs produces less toxic nanoparticles often with biologically important characteristics. The present investigation shows the biosynthesis of silver nanoparticles (AgNPs) using Trichoderma strains culture filtrate and studies the effect of antibacterial activity against Enterococcus pernyi, and its effect on growth and development of oak silkworm as well as its control to Empty-gut disease of oak silkworm. Silver nanoparticles were characterized by UV–vis spectroscopy, X-ray diffraction (XRD), Transmission Electron Microscope (TEM) and Fourier Transform Infrared Spectroscopy (FTIR). It was found that the amounts and antibacterial activities to E. pernyi of biosynthesized AgNPs from Trichoderma strains were different. The crystalline structured nanoparticles with spherical in size range from 5 to 35 nm. FTIR revealed the functional group moieties involved as a capping and reducing agent in AgNPs biosynthesis. The AgNPs - TL - CL with higher antibacterial activity at low concentrations (< 100 mg/L) led to higher feeding amounts and faster growth, extending the duration of 2nd instar, increasing the body weight of oak silkworm larvae. AgNPs - TL - CL could effectively control the occurrence of oak silkworm empty-gut disease and improve the survival rate of oak silkworm. AgNPs biosynthesized with Trichoderma sp. have the great potential as an effective antibacterial agent to control Empty - gut disease of A. pernyi.