Síntese de nanopartículas de prata por fungos endofíticos isolados de guaranazeiro e seu efeito contra fitopatógenos

Abstract

Nanotechnology is the science field that develops the synthesis and use of nanometer-scale materials (1-100 nm). Due to its unique properties, the application of metallic nanoparticles i s becoming increasingly prevalent. Among metallic nanoparticles, silver nanoparticles are the most widely used in areas such as agriculture, biotechnology, medicine, and others. The use of nanoparticles in agriculture represents an important technological innovation for the production of nanofertilizers, nanoparticles or pesticides encapsulated in nanoparticles for controlled delivery. The objective of this work was to study the synthesis of silver nanoparticles by endophytic fungi obtained from guarana and to evaluate the antifungal activity of silver nanoparticles in vitro in controlling the phytopathogens: Colletotrichum guaranicola, Colletotrichum spp. and Corynespora cassiicola. In this study, 90 isolates of endophytic fungi were tested for the production of silver nanoparticles. The characterization of silver nanoparticles was performed by UV-vis spectroscopy and scanning electron microscopy (SEM). Through the UV-Vis spectroscopy it was possible to determine the presence of silver nanoparticles in four reaction solutions by the observation of absorption bands in the 400 and 500 nm region. Through the evaluation of mycelial growth and sporulation, it was observed that synthesized nanoparticles presented strong antifungal activity mainly against the phytopathogen C. guaranicola, thus demonstrating the possibility of using biosynthesized silver nanoparticles in the control of phytopathogens, as an alternative for disease control.